[PATCH V2] mmc: debugfs: add error statistics

[PATCH V2] mmc: debugfs: add error statistics

[Shaik Sajida Bhanu]

Add debugfs entry to query eMMC and SD card errors statistics.
This feature is useful for debug and testing

Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
---

Changes since V1:
	-Removed sysfs entry for eMMC and SD card error statistics and added
	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
---
 drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/mmc/core/queue.c   |   2 +
 drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
 include/linux/mmc/host.h   |  37 ++++++++++++++++
 4 files changed, 186 insertions(+), 12 deletions(-)

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 3fdbc80..40210c34 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64 val)
 DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
 	"%llu\n");
 
+static int mmc_err_state_get(void *data, u64 *val)
+{
+	struct mmc_host *host = data;
+
+	if (!host)
+		return -EINVAL;
+
+	*val = host->err_state ? 1 : 0;
+
+	return 0;
+}
+
+static int mmc_err_state_clear(void *data, u64 val)
+{
+	struct mmc_host *host = data;
+
+	if (!host)
+		return -EINVAL;
+
+	host->err_state = false;
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
+		mmc_err_state_clear, "%llu\n");
+
+static int mmc_err_stats_show(struct seq_file *file, void *data)
+{
+	struct mmc_host *host = (struct mmc_host *)file->private;
+
+	if (!host)
+		return -EINVAL;
+
+	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
+
+	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_CMD_CRC]);
+
+	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
+
+	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_DAT_CRC]);
+
+	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_ADMA]);
+
+	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_ADMA]);
+
+	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
+		   host->err_stats[MMC_ERR_TUNING]);
+
+	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
+		   host->err_stats[MMC_ERR_CMDQ_RED]);
+
+	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
+		   host->err_stats[MMC_ERR_CMDQ_GCE]);
+
+	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
+		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
+
+	seq_printf(file, "# Request Timedout:\t %d\n",
+		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
+
+	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
+		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
+
+	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
+		   host->err_stats[MMC_ERR_ICE_CFG]);
+
+	return 0;
+}
+
+static int mmc_err_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, mmc_err_stats_show, inode->i_private);
+}
+
+static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
+				   size_t cnt, loff_t *ppos)
+{
+	struct mmc_host *host = filp->f_mapping->host->i_private;
+
+	if (!host)
+		return -EINVAL;
+
+	pr_debug("%s: Resetting MMC error statistics\n", __func__);
+	memset(host->err_stats, 0, sizeof(host->err_stats));
+
+	return cnt;
+}
+
+static const struct file_operations mmc_err_stats_fops = {
+	.open	= mmc_err_stats_open,
+	.read	= seq_read,
+	.write	= mmc_err_stats_write,
+};
+
 void mmc_add_host_debugfs(struct mmc_host *host)
 {
 	struct dentry *root;
@@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
 	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
 				   &mmc_clock_fops);
 
+	debugfs_create_file("err_state", 0600, root, host,
+		&mmc_err_state);
+	debugfs_create_file("err_stats", 0600, root, host,
+		&mmc_err_stats_fops);
+
 #ifdef CONFIG_FAIL_MMC_REQUEST
 	if (fail_request)
 		setup_fault_attr(&fail_default_attr, fail_request);
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index b15c034..5243929 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
 	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
 	bool recovery_needed = false;
 
+	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
+
 	switch (issue_type) {
 	case MMC_ISSUE_ASYNC:
 	case MMC_ISSUE_DCMD:
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 07c6da1..d742051 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
 	if (host->ops->dump_vendor_regs)
 		host->ops->dump_vendor_regs(host);
 
+	mmc_debugfs_err_stats_enable(host->mmc);
 	SDHCI_DUMP("============================================\n");
 }
 EXPORT_SYMBOL_GPL(sdhci_dumpregs);
@@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
 	spin_lock_irqsave(&host->lock, flags);
 
 	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
 		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
 		       mmc_hostname(host->mmc));
 		sdhci_dumpregs(host);
@@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct timer_list *t)
 
 	if (host->data || host->data_cmd ||
 	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
 		pr_err("%s: Timeout waiting for hardware interrupt.\n",
 		       mmc_hostname(host->mmc));
 		sdhci_dumpregs(host);
@@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
 
 	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
 		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
-		if (intmask & SDHCI_INT_TIMEOUT)
+		if (intmask & SDHCI_INT_TIMEOUT) {
 			host->cmd->error = -ETIMEDOUT;
-		else
+			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
+		} else {
 			host->cmd->error = -EILSEQ;
-
+			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
+					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
+				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
+		}
 		/* Treat data command CRC error the same as data CRC error */
 		if (host->cmd->data &&
 		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) ==
@@ -3266,6 +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
 			  -ETIMEDOUT :
 			  -EILSEQ;
 
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
 		if (sdhci_auto_cmd23(host, mrq)) {
 			mrq->sbc->error = err;
 			__sdhci_finish_mrq(host, mrq);
@@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
 				host->data_cmd = NULL;
 				data_cmd->error = -ETIMEDOUT;
+				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
 				__sdhci_finish_mrq(host, data_cmd->mrq);
 				return;
 			}
@@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 		return;
 	}
 
-	if (intmask & SDHCI_INT_DATA_TIMEOUT)
+	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
 		host->data->error = -ETIMEDOUT;
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
+	}
 	else if (intmask & SDHCI_INT_DATA_END_BIT)
 		host->data->error = -EILSEQ;
 	else if ((intmask & SDHCI_INT_DATA_CRC) &&
 		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
-			!= MMC_BUS_TEST_R)
+			!= MMC_BUS_TEST_R) {
 		host->data->error = -EILSEQ;
+		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
+				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
+			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
+	}
 	else if (intmask & SDHCI_INT_ADMA_ERROR) {
 		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
 		       intmask);
 		sdhci_adma_show_error(host);
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
 		host->data->error = -EIO;
 		if (host->ops->adma_workaround)
 			host->ops->adma_workaround(host, intmask);
@@ -3905,20 +3921,33 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
 	if (!host->cqe_on)
 		return false;
 
-	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
+	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) {
 		*cmd_error = -EILSEQ;
-	else if (intmask & SDHCI_INT_TIMEOUT)
+		if (intmask & SDHCI_INT_CRC) {
+			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
+					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
+				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
+		}
+	} else if (intmask & SDHCI_INT_TIMEOUT) {
 		*cmd_error = -ETIMEDOUT;
-	else
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
+	} else
 		*cmd_error = 0;
 
-	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
+	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
 		*data_error = -EILSEQ;
-	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
+		if (intmask & SDHCI_INT_DATA_CRC) {
+			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
+					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
+				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
+		}
+	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
 		*data_error = -ETIMEDOUT;
-	else if (intmask & SDHCI_INT_ADMA_ERROR)
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
+	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
 		*data_error = -EIO;
-	else
+		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
+	} else
 		*data_error = 0;
 
 	/* Clear selected interrupts. */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7afb57c..c263f8f 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
 
 struct mmc_host;
 
+enum mmc_err_stat {
+	MMC_ERR_CMD_TIMEOUT,
+	MMC_ERR_CMD_CRC,
+	MMC_ERR_DAT_TIMEOUT,
+	MMC_ERR_DAT_CRC,
+	MMC_ERR_AUTO_CMD,
+	MMC_ERR_ADMA,
+	MMC_ERR_TUNING,
+	MMC_ERR_CMDQ_RED,
+	MMC_ERR_CMDQ_GCE,
+	MMC_ERR_CMDQ_ICCE,
+	MMC_ERR_REQ_TIMEOUT,
+	MMC_ERR_CMDQ_REQ_TIMEOUT,
+	MMC_ERR_ICE_CFG,
+	MMC_ERR_MAX,
+};
+
 struct mmc_host_ops {
 	/*
 	 * It is optional for the host to implement pre_req and post_req in
@@ -500,6 +517,8 @@ struct mmc_host {
 
 	/* Host Software Queue support */
 	bool			hsq_enabled;
+	u32                     err_stats[MMC_ERR_MAX];
+	bool			err_state;
 
 	unsigned long		private[] ____cacheline_aligned;
 };
@@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
 	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 }
 
+static inline void mmc_debugfs_err_stats_enable(struct mmc_host *mmc)
+{
+	mmc->err_state = true;
+}
+
+static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
+		enum mmc_err_stat stat) {
+
+	/*
+	 * Ignore the command timeout errors observed during
+	 * the card init as those are excepted.
+	 */
+	if (!mmc->err_state)
+		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
+
+	mmc->err_stats[stat] += 1;
+}
+
 int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error);
 int mmc_send_abort_tuning(struct mmc_host *host, u32 opcode);
 int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member 
of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH V2] mmc: debugfs: add error statistics

[Adrian Hunter]

On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
> Add debugfs entry to query eMMC and SD card errors statistics.
> This feature is useful for debug and testing
> 
> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
> ---
> 
> Changes since V1:
> 	-Removed sysfs entry for eMMC and SD card error statistics and added
> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.

Thanks for doing this.

> ---
>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/queue.c   |   2 +
>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>  4 files changed, 186 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
> index 3fdbc80..40210c34 100644
> --- a/drivers/mmc/core/debugfs.c
> +++ b/drivers/mmc/core/debugfs.c
> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64 val)
>  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>  	"%llu\n");
>  
> +static int mmc_err_state_get(void *data, u64 *val)
> +{
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	*val = host->err_state ? 1 : 0;
> +
> +	return 0;
> +}
> +
> +static int mmc_err_state_clear(void *data, u64 val)
> +{
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	host->err_state = false;

Is there much reason to disable err stats from userspace?

> +
> +	return 0;
> +}
> +
> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
> +		mmc_err_state_clear, "%llu\n");
> +
> +static int mmc_err_stats_show(struct seq_file *file, void *data)
> +{
> +	struct mmc_host *host = (struct mmc_host *)file->private;
> +
> +	if (!host)
> +		return -EINVAL;

I was thinking we needed a way to determine whether stats were being
collected because not all drivers would support it at least initially
e.g.

	if (!host->err_stats_enabled) {
		seq_printf(file, "Not supported by driver\n");
		return 0;
	}

> +
> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);

Maybe put the descriptions in an array and iterate e.g.

	const char *desc[MMC_ERR_MAX] = {
		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
		etc
	};
	int i;

	if (!host)
		return -EINVAL;

	for (i = 0; i < MMC_ERR_MAX; i++) {
		if (desc[i])
			seq_printf(file, "# %s:\t %d\n",
				   desc[1], host->err_stats[i]);
	}

> +
> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_CRC]);
> +
> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
> +
> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_CRC]);
> +
> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_TUNING]);
> +
> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
> +
> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
> +
> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
> +
> +	seq_printf(file, "# Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_ICE_CFG]);
> +
> +	return 0;
> +}
> +
> +static int mmc_err_stats_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, mmc_err_stats_show, inode->i_private);
> +}
> +
> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
> +				   size_t cnt, loff_t *ppos)
> +{
> +	struct mmc_host *host = filp->f_mapping->host->i_private;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
> +	memset(host->err_stats, 0, sizeof(host->err_stats));
> +
> +	return cnt;
> +}
> +
> +static const struct file_operations mmc_err_stats_fops = {
> +	.open	= mmc_err_stats_open,
> +	.read	= seq_read,
> +	.write	= mmc_err_stats_write,
> +};
> +
>  void mmc_add_host_debugfs(struct mmc_host *host)
>  {
>  	struct dentry *root;
> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>  				   &mmc_clock_fops);
>  
> +	debugfs_create_file("err_state", 0600, root, host,
> +		&mmc_err_state);
> +	debugfs_create_file("err_stats", 0600, root, host,
> +		&mmc_err_stats_fops);
> +
>  #ifdef CONFIG_FAIL_MMC_REQUEST
>  	if (fail_request)
>  		setup_fault_attr(&fail_default_attr, fail_request);
> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
> index b15c034..5243929 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>  	bool recovery_needed = false;
>  
> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
> +
>  	switch (issue_type) {
>  	case MMC_ISSUE_ASYNC:
>  	case MMC_ISSUE_DCMD:
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c

I think the core changes should be a separate patch from sdhci.
I would probably split into 4:
	mmc core
	mmc block driver
	cqhci driver
	sdhci driver

> index 07c6da1..d742051 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>  	if (host->ops->dump_vendor_regs)
>  		host->ops->dump_vendor_regs(host);
>  
> +	mmc_debugfs_err_stats_enable(host->mmc);

Why here and not in e.g. __sdhci_add_host() ?

>  	SDHCI_DUMP("============================================\n");
>  }
>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>  	spin_lock_irqsave(&host->lock, flags);
>  
>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct timer_list *t)
>  
>  	if (host->data || host->data_cmd ||
>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
>  
>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
> -		if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_TIMEOUT) {
>  			host->cmd->error = -ETIMEDOUT;
> -		else
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +		} else {
>  			host->cmd->error = -EILSEQ;
> -
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
>  		/* Treat data command CRC error the same as data CRC error */
>  		if (host->cmd->data &&
>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) ==
> @@ -3266,6 +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
>  			  -ETIMEDOUT :
>  			  -EILSEQ;
>  
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>  		if (sdhci_auto_cmd23(host, mrq)) {
>  			mrq->sbc->error = err;
>  			__sdhci_finish_mrq(host, mrq);
> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  				host->data_cmd = NULL;
>  				data_cmd->error = -ETIMEDOUT;
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>  				return;
>  			}
> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  		return;
>  	}
>  
> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		host->data->error = -ETIMEDOUT;
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	}
>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>  		host->data->error = -EILSEQ;
>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
> -			!= MMC_BUS_TEST_R)
> +			!= MMC_BUS_TEST_R) {
>  		host->data->error = -EILSEQ;
> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +	}
>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>  		       intmask);
>  		sdhci_adma_show_error(host);
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>  		host->data->error = -EIO;
>  		if (host->ops->adma_workaround)
>  			host->ops->adma_workaround(host, intmask);
> @@ -3905,20 +3921,33 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>  	if (!host->cqe_on)
>  		return false;
>  
> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) {
>  		*cmd_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>  		*cmd_error = -ETIMEDOUT;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +	} else
>  		*cmd_error = 0;
>  
> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>  		*data_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +		if (intmask & SDHCI_INT_DATA_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		*data_error = -ETIMEDOUT;
> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		*data_error = -EIO;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
> +	} else
>  		*data_error = 0;
>  
>  	/* Clear selected interrupts. */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 7afb57c..c263f8f 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>  
>  struct mmc_host;
>  
> +enum mmc_err_stat {
> +	MMC_ERR_CMD_TIMEOUT,
> +	MMC_ERR_CMD_CRC,
> +	MMC_ERR_DAT_TIMEOUT,
> +	MMC_ERR_DAT_CRC,
> +	MMC_ERR_AUTO_CMD,
> +	MMC_ERR_ADMA,
> +	MMC_ERR_TUNING,
> +	MMC_ERR_CMDQ_RED,
> +	MMC_ERR_CMDQ_GCE,
> +	MMC_ERR_CMDQ_ICCE,
> +	MMC_ERR_REQ_TIMEOUT,
> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
> +	MMC_ERR_ICE_CFG,
> +	MMC_ERR_MAX,
> +};
> +
>  struct mmc_host_ops {
>  	/*
>  	 * It is optional for the host to implement pre_req and post_req in
> @@ -500,6 +517,8 @@ struct mmc_host {
>  
>  	/* Host Software Queue support */
>  	bool			hsq_enabled;
> +	u32                     err_stats[MMC_ERR_MAX];

If you make it u64 then we don't have to think about the value overflowing.

> +	bool			err_state;
>  
>  	unsigned long		private[] ____cacheline_aligned;
>  };
> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
>  }
>  
> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host *mmc)
> +{
> +	mmc->err_state = true;
> +}
> +
> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
> +		enum mmc_err_stat stat) {
> +
> +	/*
> +	 * Ignore the command timeout errors observed during
> +	 * the card init as those are excepted.
> +	 */
> +	if (!mmc->err_state)
> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;

This would be better handled in the card init code somewhere, not here.

> +
> +	mmc->err_stats[stat] += 1;
> +}
> +
>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error);
>  int mmc_send_abort_tuning(struct mmc_host *host, u32 opcode);
>  int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd);
> 

RE: [PATCH V2] mmc: debugfs: add error statistics

[Sajida Bhanu (Temp) (QUIC)]

Hi Adrian,

Thanks for the review.

Please find the inline comments.

Thanks,
Sajida

-----Original Message-----
From: Adrian Hunter <adrian.hunter@intel.com> 
Sent: Wednesday, December 15, 2021 7:33 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: Re: [PATCH V2] mmc: debugfs: add error statistics

On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
> Add debugfs entry to query eMMC and SD card errors statistics.
> This feature is useful for debug and testing
> 
> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
> ---
> 
> Changes since V1:
> 	-Removed sysfs entry for eMMC and SD card error statistics and added
> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.

Thanks for doing this.

> ---
>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/queue.c   |   2 +
>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>  4 files changed, 186 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
> index 3fdbc80..40210c34 100644
> --- a/drivers/mmc/core/debugfs.c
> +++ b/drivers/mmc/core/debugfs.c
> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64 
> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>  	"%llu\n");
>  
> +static int mmc_err_state_get(void *data, u64 *val) {
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	*val = host->err_state ? 1 : 0;
> +
> +	return 0;
> +}
> +
> +static int mmc_err_state_clear(void *data, u64 val) {
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	host->err_state = false;

Is there much reason to disable err stats from userspace?

>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.

> +
> +	return 0;
> +}
> +
> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
> +		mmc_err_state_clear, "%llu\n");
> +
> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
> +	struct mmc_host *host = (struct mmc_host *)file->private;
> +
> +	if (!host)
> +		return -EINVAL;

I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.

	if (!host->err_stats_enabled) {
		seq_printf(file, "Not supported by driver\n");
		return 0;
	}

>>>>>>>You mean declare another variable (err_stats_enabled) and enable it in probe?

> +
> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);

Maybe put the descriptions in an array and iterate e.g.

	const char *desc[MMC_ERR_MAX] = {
		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
		etc
	};
	int i;

	if (!host)
		return -EINVAL;

	for (i = 0; i < MMC_ERR_MAX; i++) {
		if (desc[i])
			seq_printf(file, "# %s:\t %d\n",
				   desc[1], host->err_stats[i]);
	}

>>>>>>> Sure 

> +
> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_CRC]);
> +
> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
> +
> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_CRC]);
> +
> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_TUNING]);
> +
> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
> +
> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
> +
> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
> +
> +	seq_printf(file, "# Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_ICE_CFG]);
> +
> +	return 0;
> +}
> +
> +static int mmc_err_stats_open(struct inode *inode, struct file *file) 
> +{
> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
> +
> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
> +				   size_t cnt, loff_t *ppos)
> +{
> +	struct mmc_host *host = filp->f_mapping->host->i_private;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
> +	memset(host->err_stats, 0, sizeof(host->err_stats));
> +
> +	return cnt;
> +}
> +
> +static const struct file_operations mmc_err_stats_fops = {
> +	.open	= mmc_err_stats_open,
> +	.read	= seq_read,
> +	.write	= mmc_err_stats_write,
> +};
> +
>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>  	struct dentry *root;
> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>  				   &mmc_clock_fops);
>  
> +	debugfs_create_file("err_state", 0600, root, host,
> +		&mmc_err_state);
> +	debugfs_create_file("err_stats", 0600, root, host,
> +		&mmc_err_stats_fops);
> +
>  #ifdef CONFIG_FAIL_MMC_REQUEST
>  	if (fail_request)
>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 
> b15c034..5243929 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>  	bool recovery_needed = false;
>  
> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
> +
>  	switch (issue_type) {
>  	case MMC_ISSUE_ASYNC:
>  	case MMC_ISSUE_DCMD:
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c

I think the core changes should be a separate patch from sdhci.
I would probably split into 4:
	mmc core
	mmc block driver
	cqhci driver
	sdhci driver

>>>> Sure

> index 07c6da1..d742051 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>  	if (host->ops->dump_vendor_regs)
>  		host->ops->dump_vendor_regs(host);
>  
> +	mmc_debugfs_err_stats_enable(host->mmc);

Why here and not in e.g. __sdhci_add_host() ?

>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.

>  	SDHCI_DUMP("============================================\n");
>  }
>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>  	spin_lock_irqsave(&host->lock, flags);
>  
>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
> timer_list *t)
>  
>  	if (host->data || host->data_cmd ||
>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
> *host, u32 intmask, u32 *intmask_p)
>  
>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
> -		if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_TIMEOUT) {
>  			host->cmd->error = -ETIMEDOUT;
> -		else
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +		} else {
>  			host->cmd->error = -EILSEQ;
> -
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
>  		/* Treat data command CRC error the same as data CRC error */
>  		if (host->cmd->data &&
>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6 
> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
>  			  -ETIMEDOUT :
>  			  -EILSEQ;
>  
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>  		if (sdhci_auto_cmd23(host, mrq)) {
>  			mrq->sbc->error = err;
>  			__sdhci_finish_mrq(host, mrq);
> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  				host->data_cmd = NULL;
>  				data_cmd->error = -ETIMEDOUT;
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>  				return;
>  			}
> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  		return;
>  	}
>  
> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		host->data->error = -ETIMEDOUT;
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	}
>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>  		host->data->error = -EILSEQ;
>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
> -			!= MMC_BUS_TEST_R)
> +			!= MMC_BUS_TEST_R) {
>  		host->data->error = -EILSEQ;
> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +	}
>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>  		       intmask);
>  		sdhci_adma_show_error(host);
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>  		host->data->error = -EIO;
>  		if (host->ops->adma_workaround)
>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 @@ 
> bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>  	if (!host->cqe_on)
>  		return false;
>  
> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) 
> +{
>  		*cmd_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>  		*cmd_error = -ETIMEDOUT;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +	} else
>  		*cmd_error = 0;
>  
> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>  		*data_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +		if (intmask & SDHCI_INT_DATA_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		*data_error = -ETIMEDOUT;
> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		*data_error = -EIO;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
> +	} else
>  		*data_error = 0;
>  
>  	/* Clear selected interrupts. */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 
> 7afb57c..c263f8f 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>  
>  struct mmc_host;
>  
> +enum mmc_err_stat {
> +	MMC_ERR_CMD_TIMEOUT,
> +	MMC_ERR_CMD_CRC,
> +	MMC_ERR_DAT_TIMEOUT,
> +	MMC_ERR_DAT_CRC,
> +	MMC_ERR_AUTO_CMD,
> +	MMC_ERR_ADMA,
> +	MMC_ERR_TUNING,
> +	MMC_ERR_CMDQ_RED,
> +	MMC_ERR_CMDQ_GCE,
> +	MMC_ERR_CMDQ_ICCE,
> +	MMC_ERR_REQ_TIMEOUT,
> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
> +	MMC_ERR_ICE_CFG,
> +	MMC_ERR_MAX,
> +};
> +
>  struct mmc_host_ops {
>  	/*
>  	 * It is optional for the host to implement pre_req and post_req in 
> @@ -500,6 +517,8 @@ struct mmc_host {
>  
>  	/* Host Software Queue support */
>  	bool			hsq_enabled;
> +	u32                     err_stats[MMC_ERR_MAX];

If you make it u64 then we don't have to think about the value overflowing.

>>> Sure

> +	bool			err_state;
>  
>  	unsigned long		private[] ____cacheline_aligned;
>  };
> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
> DMA_FROM_DEVICE;  }
>  
> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host *mmc) 
> +{
> +	mmc->err_state = true;
> +}
> +
> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
> +		enum mmc_err_stat stat) {
> +
> +	/*
> +	 * Ignore the command timeout errors observed during
> +	 * the card init as those are excepted.
> +	 */
> +	if (!mmc->err_state)
> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;

This would be better handled in the card init code somewhere, not here.

>>>> Sure.

> +
> +	mmc->err_stats[stat] += 1;
> +}
> +
>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
> **new_ext_csd);
> 

RE: [PATCH V2] mmc: debugfs: add error statistics

[Sajida Bhanu (Temp) (QUIC)]

Gentle Reminder!!!

Thanks,
Sajida

-----Original Message-----
From: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com> 
Sent: Tuesday, December 21, 2021 12:46 PM
To: Adrian Hunter <adrian.hunter@intel.com>; Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: RE: [PATCH V2] mmc: debugfs: add error statistics

Hi Adrian,

Thanks for the review.

Please find the inline comments.

Thanks,
Sajida

-----Original Message-----
From: Adrian Hunter <adrian.hunter@intel.com>
Sent: Wednesday, December 15, 2021 7:33 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: Re: [PATCH V2] mmc: debugfs: add error statistics

On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
> Add debugfs entry to query eMMC and SD card errors statistics.
> This feature is useful for debug and testing
> 
> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
> ---
> 
> Changes since V1:
> 	-Removed sysfs entry for eMMC and SD card error statistics and added
> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.

Thanks for doing this.

> ---
>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/queue.c   |   2 +
>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>  4 files changed, 186 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
> index 3fdbc80..40210c34 100644
> --- a/drivers/mmc/core/debugfs.c
> +++ b/drivers/mmc/core/debugfs.c
> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>  	"%llu\n");
>  
> +static int mmc_err_state_get(void *data, u64 *val) {
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	*val = host->err_state ? 1 : 0;
> +
> +	return 0;
> +}
> +
> +static int mmc_err_state_clear(void *data, u64 val) {
> +	struct mmc_host *host = data;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	host->err_state = false;

Is there much reason to disable err stats from userspace?

>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.

> +
> +	return 0;
> +}
> +
> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
> +		mmc_err_state_clear, "%llu\n");
> +
> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
> +	struct mmc_host *host = (struct mmc_host *)file->private;
> +
> +	if (!host)
> +		return -EINVAL;

I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.

	if (!host->err_stats_enabled) {
		seq_printf(file, "Not supported by driver\n");
		return 0;
	}

>>>>>>>You mean declare another variable (err_stats_enabled) and enable it in probe?

> +
> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);

Maybe put the descriptions in an array and iterate e.g.

	const char *desc[MMC_ERR_MAX] = {
		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
		etc
	};
	int i;

	if (!host)
		return -EINVAL;

	for (i = 0; i < MMC_ERR_MAX; i++) {
		if (desc[i])
			seq_printf(file, "# %s:\t %d\n",
				   desc[1], host->err_stats[i]);
	}

>>>>>>> Sure

> +
> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMD_CRC]);
> +
> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
> +
> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_DAT_CRC]);
> +
> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_ADMA]);
> +
> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
> +		   host->err_stats[MMC_ERR_TUNING]);
> +
> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
> +
> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
> +
> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
> +
> +	seq_printf(file, "# Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
> +
> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
> +		   host->err_stats[MMC_ERR_ICE_CFG]);
> +
> +	return 0;
> +}
> +
> +static int mmc_err_stats_open(struct inode *inode, struct file *file) 
> +{
> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
> +
> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
> +				   size_t cnt, loff_t *ppos)
> +{
> +	struct mmc_host *host = filp->f_mapping->host->i_private;
> +
> +	if (!host)
> +		return -EINVAL;
> +
> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
> +	memset(host->err_stats, 0, sizeof(host->err_stats));
> +
> +	return cnt;
> +}
> +
> +static const struct file_operations mmc_err_stats_fops = {
> +	.open	= mmc_err_stats_open,
> +	.read	= seq_read,
> +	.write	= mmc_err_stats_write,
> +};
> +
>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>  	struct dentry *root;
> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>  				   &mmc_clock_fops);
>  
> +	debugfs_create_file("err_state", 0600, root, host,
> +		&mmc_err_state);
> +	debugfs_create_file("err_stats", 0600, root, host,
> +		&mmc_err_stats_fops);
> +
>  #ifdef CONFIG_FAIL_MMC_REQUEST
>  	if (fail_request)
>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
> b15c034..5243929 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>  	bool recovery_needed = false;
>  
> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
> +
>  	switch (issue_type) {
>  	case MMC_ISSUE_ASYNC:
>  	case MMC_ISSUE_DCMD:
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c

I think the core changes should be a separate patch from sdhci.
I would probably split into 4:
	mmc core
	mmc block driver
	cqhci driver
	sdhci driver

>>>> Sure

> index 07c6da1..d742051 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>  	if (host->ops->dump_vendor_regs)
>  		host->ops->dump_vendor_regs(host);
>  
> +	mmc_debugfs_err_stats_enable(host->mmc);

Why here and not in e.g. __sdhci_add_host() ?

>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.

>  	SDHCI_DUMP("============================================\n");
>  }
>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>  	spin_lock_irqsave(&host->lock, flags);
>  
>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
> timer_list *t)
>  
>  	if (host->data || host->data_cmd ||
>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>  		       mmc_hostname(host->mmc));
>  		sdhci_dumpregs(host);
> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
> *host, u32 intmask, u32 *intmask_p)
>  
>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
> -		if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_TIMEOUT) {
>  			host->cmd->error = -ETIMEDOUT;
> -		else
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +		} else {
>  			host->cmd->error = -EILSEQ;
> -
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
>  		/* Treat data command CRC error the same as data CRC error */
>  		if (host->cmd->data &&
>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6
> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
> +intmask, u32 *intmask_p)
>  			  -ETIMEDOUT :
>  			  -EILSEQ;
>  
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>  		if (sdhci_auto_cmd23(host, mrq)) {
>  			mrq->sbc->error = err;
>  			__sdhci_finish_mrq(host, mrq);
> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  				host->data_cmd = NULL;
>  				data_cmd->error = -ETIMEDOUT;
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>  				return;
>  			}
> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  		return;
>  	}
>  
> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		host->data->error = -ETIMEDOUT;
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	}
>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>  		host->data->error = -EILSEQ;
>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
> -			!= MMC_BUS_TEST_R)
> +			!= MMC_BUS_TEST_R) {
>  		host->data->error = -EILSEQ;
> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +	}
>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>  		       intmask);
>  		sdhci_adma_show_error(host);
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>  		host->data->error = -EIO;
>  		if (host->ops->adma_workaround)
>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 @@ 
> bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>  	if (!host->cqe_on)
>  		return false;
>  
> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) 
> +{
>  		*cmd_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_TIMEOUT)
> +		if (intmask & SDHCI_INT_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>  		*cmd_error = -ETIMEDOUT;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
> +	} else
>  		*cmd_error = 0;
>  
> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>  		*data_error = -EILSEQ;
> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
> +		if (intmask & SDHCI_INT_DATA_CRC) {
> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
> +		}
> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		*data_error = -ETIMEDOUT;
> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>  		*data_error = -EIO;
> -	else
> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
> +	} else
>  		*data_error = 0;
>  
>  	/* Clear selected interrupts. */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 
> 7afb57c..c263f8f 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>  
>  struct mmc_host;
>  
> +enum mmc_err_stat {
> +	MMC_ERR_CMD_TIMEOUT,
> +	MMC_ERR_CMD_CRC,
> +	MMC_ERR_DAT_TIMEOUT,
> +	MMC_ERR_DAT_CRC,
> +	MMC_ERR_AUTO_CMD,
> +	MMC_ERR_ADMA,
> +	MMC_ERR_TUNING,
> +	MMC_ERR_CMDQ_RED,
> +	MMC_ERR_CMDQ_GCE,
> +	MMC_ERR_CMDQ_ICCE,
> +	MMC_ERR_REQ_TIMEOUT,
> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
> +	MMC_ERR_ICE_CFG,
> +	MMC_ERR_MAX,
> +};
> +
>  struct mmc_host_ops {
>  	/*
>  	 * It is optional for the host to implement pre_req and post_req in 
> @@ -500,6 +517,8 @@ struct mmc_host {
>  
>  	/* Host Software Queue support */
>  	bool			hsq_enabled;
> +	u32                     err_stats[MMC_ERR_MAX];

If you make it u64 then we don't have to think about the value overflowing.

>>> Sure

> +	bool			err_state;
>  
>  	unsigned long		private[] ____cacheline_aligned;
>  };
> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
> DMA_FROM_DEVICE;  }
>  
> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host *mmc) 
> +{
> +	mmc->err_state = true;
> +}
> +
> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
> +		enum mmc_err_stat stat) {
> +
> +	/*
> +	 * Ignore the command timeout errors observed during
> +	 * the card init as those are excepted.
> +	 */
> +	if (!mmc->err_state)
> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;

This would be better handled in the card init code somewhere, not here.

>>>> Sure.

> +
> +	mmc->err_stats[stat] += 1;
> +}
> +
>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
> **new_ext_csd);
> 

Re: [PATCH V2] mmc: debugfs: add error statistics

[Adrian Hunter]

On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments.

I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.

> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com> 
> Sent: Wednesday, December 15, 2021 7:33 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>> Add debugfs entry to query eMMC and SD card errors statistics.
>> This feature is useful for debug and testing
>>
>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>> ---
>>
>> Changes since V1:
>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
> 
> Thanks for doing this.
> 
>> ---
>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>  drivers/mmc/core/queue.c   |   2 +
>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
>> index 3fdbc80..40210c34 100644
>> --- a/drivers/mmc/core/debugfs.c
>> +++ b/drivers/mmc/core/debugfs.c
>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64 
>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>  	"%llu\n");
>>  
>> +static int mmc_err_state_get(void *data, u64 *val) {
>> +	struct mmc_host *host = data;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	*val = host->err_state ? 1 : 0;
>> +
>> +	return 0;
>> +}
>> +
>> +static int mmc_err_state_clear(void *data, u64 val) {
>> +	struct mmc_host *host = data;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	host->err_state = false;
> 
> Is there much reason to disable err stats from userspace?
> 
>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.

That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.

> 
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>> +		mmc_err_state_clear, "%llu\n");
>> +
>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>> +
>> +	if (!host)
>> +		return -EINVAL;
> 
> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
> 
> 	if (!host->err_stats_enabled) {
> 		seq_printf(file, "Not supported by driver\n");
> 		return 0;
> 	}
> 
>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?

Yes, although it is not clear if this is the same as what you want from err_state,
i.e. is err_state different from err_stats_enabled?

> 
>> +
>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
> 
> Maybe put the descriptions in an array and iterate e.g.
> 
> 	const char *desc[MMC_ERR_MAX] = {
> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
> 		etc
> 	};
> 	int i;
> 
> 	if (!host)
> 		return -EINVAL;
> 
> 	for (i = 0; i < MMC_ERR_MAX; i++) {
> 		if (desc[i])
> 			seq_printf(file, "# %s:\t %d\n",
> 				   desc[1], host->err_stats[i]);
> 	}
> 
>>>>>>>> Sure 
> 
>> +
>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>> +
>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>> +
>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>> +
>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_ADMA]);
>> +
>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_ADMA]);
>> +
>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_TUNING]);
>> +
>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>> +
>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>> +
>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>> +
>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>> +
>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>> +
>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>> +
>> +	return 0;
>> +}
>> +
>> +static int mmc_err_stats_open(struct inode *inode, struct file *file) 
>> +{
>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>> +
>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>> +				   size_t cnt, loff_t *ppos)
>> +{
>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>> +
>> +	return cnt;
>> +}
>> +
>> +static const struct file_operations mmc_err_stats_fops = {
>> +	.open	= mmc_err_stats_open,
>> +	.read	= seq_read,
>> +	.write	= mmc_err_stats_write,
>> +};
>> +
>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>  	struct dentry *root;
>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>  				   &mmc_clock_fops);
>>  
>> +	debugfs_create_file("err_state", 0600, root, host,
>> +		&mmc_err_state);
>> +	debugfs_create_file("err_stats", 0600, root, host,
>> +		&mmc_err_stats_fops);
>> +
>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>  	if (fail_request)
>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 
>> b15c034..5243929 100644
>> --- a/drivers/mmc/core/queue.c
>> +++ b/drivers/mmc/core/queue.c
>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>  	bool recovery_needed = false;
>>  
>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>> +
>>  	switch (issue_type) {
>>  	case MMC_ISSUE_ASYNC:
>>  	case MMC_ISSUE_DCMD:
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> 
> I think the core changes should be a separate patch from sdhci.
> I would probably split into 4:
> 	mmc core
> 	mmc block driver
> 	cqhci driver
> 	sdhci driver
> 
>>>>> Sure
> 
>> index 07c6da1..d742051 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>  	if (host->ops->dump_vendor_regs)
>>  		host->ops->dump_vendor_regs(host);
>>  
>> +	mmc_debugfs_err_stats_enable(host->mmc);
> 
> Why here and not in e.g. __sdhci_add_host() ?
> 
>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.

Registers are not dumped for most errors.  Please move this to __sdhci_add_host().

> 
>>  	SDHCI_DUMP("============================================\n");
>>  }
>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>  	spin_lock_irqsave(&host->lock, flags);
>>  
>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>  		       mmc_hostname(host->mmc));
>>  		sdhci_dumpregs(host);
>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>> timer_list *t)
>>  
>>  	if (host->data || host->data_cmd ||
>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>  		       mmc_hostname(host->mmc));
>>  		sdhci_dumpregs(host);
>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>> *host, u32 intmask, u32 *intmask_p)
>>  
>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>> -		if (intmask & SDHCI_INT_TIMEOUT)
>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>  			host->cmd->error = -ETIMEDOUT;
>> -		else
>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>> +		} else {
>>  			host->cmd->error = -EILSEQ;
>> -
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>> +		}
>>  		/* Treat data command CRC error the same as data CRC error */
>>  		if (host->cmd->data &&
>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6 
>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
>>  			  -ETIMEDOUT :
>>  			  -EILSEQ;
>>  
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>  			mrq->sbc->error = err;
>>  			__sdhci_finish_mrq(host, mrq);
>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  				host->data_cmd = NULL;
>>  				data_cmd->error = -ETIMEDOUT;
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>  				return;
>>  			}
>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>  		return;
>>  	}
>>  
>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  		host->data->error = -ETIMEDOUT;
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>> +	}
>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>  		host->data->error = -EILSEQ;
>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>> -			!= MMC_BUS_TEST_R)
>> +			!= MMC_BUS_TEST_R) {
>>  		host->data->error = -EILSEQ;
>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>> +	}
>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>  		       intmask);
>>  		sdhci_adma_show_error(host);
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>  		host->data->error = -EIO;
>>  		if (host->ops->adma_workaround)
>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 @@ 
>> bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>  	if (!host->cqe_on)
>>  		return false;
>>  
>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) 
>> +{
>>  		*cmd_error = -EILSEQ;
>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>> +		if (intmask & SDHCI_INT_CRC) {
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>> +		}
>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>  		*cmd_error = -ETIMEDOUT;
>> -	else
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>> +	} else
>>  		*cmd_error = 0;
>>  
>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>  		*data_error = -EILSEQ;
>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>> +		}
>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  		*data_error = -ETIMEDOUT;
>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>  		*data_error = -EIO;
>> -	else
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>> +	} else
>>  		*data_error = 0;
>>  
>>  	/* Clear selected interrupts. */
>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 
>> 7afb57c..c263f8f 100644
>> --- a/include/linux/mmc/host.h
>> +++ b/include/linux/mmc/host.h
>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>  
>>  struct mmc_host;
>>  
>> +enum mmc_err_stat {
>> +	MMC_ERR_CMD_TIMEOUT,
>> +	MMC_ERR_CMD_CRC,
>> +	MMC_ERR_DAT_TIMEOUT,
>> +	MMC_ERR_DAT_CRC,
>> +	MMC_ERR_AUTO_CMD,
>> +	MMC_ERR_ADMA,
>> +	MMC_ERR_TUNING,
>> +	MMC_ERR_CMDQ_RED,
>> +	MMC_ERR_CMDQ_GCE,
>> +	MMC_ERR_CMDQ_ICCE,
>> +	MMC_ERR_REQ_TIMEOUT,
>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>> +	MMC_ERR_ICE_CFG,
>> +	MMC_ERR_MAX,
>> +};
>> +
>>  struct mmc_host_ops {
>>  	/*
>>  	 * It is optional for the host to implement pre_req and post_req in 
>> @@ -500,6 +517,8 @@ struct mmc_host {
>>  
>>  	/* Host Software Queue support */
>>  	bool			hsq_enabled;
>> +	u32                     err_stats[MMC_ERR_MAX];
> 
> If you make it u64 then we don't have to think about the value overflowing.
> 
>>>> Sure
> 
>> +	bool			err_state;
>>  
>>  	unsigned long		private[] ____cacheline_aligned;
>>  };
>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>> DMA_FROM_DEVICE;  }
>>  
>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host *mmc) 
>> +{
>> +	mmc->err_state = true;
>> +}
>> +
>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>> +		enum mmc_err_stat stat) {
>> +
>> +	/*
>> +	 * Ignore the command timeout errors observed during
>> +	 * the card init as those are excepted.
>> +	 */
>> +	if (!mmc->err_state)
>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
> 
> This would be better handled in the card init code somewhere, not here.
> 
>>>>> Sure.
> 
>> +
>> +	mmc->err_stats[stat] += 1;
>> +}
>> +
>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>> **new_ext_csd);
>>
> 

RE: [PATCH V2] mmc: debugfs: add error statistics

[Sajida Bhanu (Temp) (QUIC)]

Hi Adrian,

Thanks for the review.

Please find the inline comments.

Thanks,
Sajida

-----Original Message-----
From: Adrian Hunter <adrian.hunter@intel.com> 
Sent: Monday, January 3, 2022 3:20 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: Re: [PATCH V2] mmc: debugfs: add error statistics

On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments.

I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.

> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Wednesday, December 15, 2021 7:33 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
> ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; 
> linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; 
> linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
> nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>> Add debugfs entry to query eMMC and SD card errors statistics.
>> This feature is useful for debug and testing
>>
>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>> ---
>>
>> Changes since V1:
>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
> 
> Thanks for doing this.
> 
>> ---
>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>  drivers/mmc/core/queue.c   |   2 +
>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
>> index 3fdbc80..40210c34 100644
>> --- a/drivers/mmc/core/debugfs.c
>> +++ b/drivers/mmc/core/debugfs.c
>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>  	"%llu\n");
>>  
>> +static int mmc_err_state_get(void *data, u64 *val) {
>> +	struct mmc_host *host = data;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	*val = host->err_state ? 1 : 0;
>> +
>> +	return 0;
>> +}
>> +
>> +static int mmc_err_state_clear(void *data, u64 val) {
>> +	struct mmc_host *host = data;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	host->err_state = false;
> 
> Is there much reason to disable err stats from userspace?
> 
>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.

That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.

>>>>>> If user wants to explicitly clear then he can use this.

> 
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>> +		mmc_err_state_clear, "%llu\n");
>> +
>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>> +
>> +	if (!host)
>> +		return -EINVAL;
> 
> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
> 
> 	if (!host->err_stats_enabled) {
> 		seq_printf(file, "Not supported by driver\n");
> 		return 0;
> 	}
> 
>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?

Yes, although it is not clear if this is the same as what you want from err_state, i.e. is err_state different from err_stats_enabled?

>>>>> Yes, err_state and err_stats_enabled both are different.  err_state will be set if any errors happened in driver level. 
 err_stats_enabled will be set  if err_stats feature enabled,  if any vendor wants to use err_stats feature they will set this err_stats_enabled in their vendor specific file.

> 
>> +
>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
> 
> Maybe put the descriptions in an array and iterate e.g.
> 
> 	const char *desc[MMC_ERR_MAX] = {
> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
> 		etc
> 	};
> 	int i;
> 
> 	if (!host)
> 		return -EINVAL;
> 
> 	for (i = 0; i < MMC_ERR_MAX; i++) {
> 		if (desc[i])
> 			seq_printf(file, "# %s:\t %d\n",
> 				   desc[1], host->err_stats[i]);
> 	}
> 
>>>>>>>> Sure
> 
>> +
>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>> +
>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>> +
>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>> +
>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_ADMA]);
>> +
>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_ADMA]);
>> +
>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>> +		   host->err_stats[MMC_ERR_TUNING]);
>> +
>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>> +
>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>> +
>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>> +
>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>> +
>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>> +
>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>> +
>> +	return 0;
>> +}
>> +
>> +static int mmc_err_stats_open(struct inode *inode, struct file 
>> +*file) {
>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>> +
>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>> +				   size_t cnt, loff_t *ppos)
>> +{
>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>> +
>> +	if (!host)
>> +		return -EINVAL;
>> +
>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>> +
>> +	return cnt;
>> +}
>> +
>> +static const struct file_operations mmc_err_stats_fops = {
>> +	.open	= mmc_err_stats_open,
>> +	.read	= seq_read,
>> +	.write	= mmc_err_stats_write,
>> +};
>> +
>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>  	struct dentry *root;
>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>  				   &mmc_clock_fops);
>>  
>> +	debugfs_create_file("err_state", 0600, root, host,
>> +		&mmc_err_state);
>> +	debugfs_create_file("err_stats", 0600, root, host,
>> +		&mmc_err_stats_fops);
>> +
>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>  	if (fail_request)
>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
>> b15c034..5243929 100644
>> --- a/drivers/mmc/core/queue.c
>> +++ b/drivers/mmc/core/queue.c
>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>  	bool recovery_needed = false;
>>  
>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>> +
>>  	switch (issue_type) {
>>  	case MMC_ISSUE_ASYNC:
>>  	case MMC_ISSUE_DCMD:
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> 
> I think the core changes should be a separate patch from sdhci.
> I would probably split into 4:
> 	mmc core
> 	mmc block driver
> 	cqhci driver
> 	sdhci driver
> 
>>>>> Sure
> 
>> index 07c6da1..d742051 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>  	if (host->ops->dump_vendor_regs)
>>  		host->ops->dump_vendor_regs(host);
>>  
>> +	mmc_debugfs_err_stats_enable(host->mmc);
> 
> Why here and not in e.g. __sdhci_add_host() ?
> 
>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.

Registers are not dumped for most errors.  Please move this to __sdhci_add_host().

>>>> err_state is true means errors happened in driver level and for most of the errors we are dumping the registers, so I am thinking it is better to have this call in sdhci_dumpregs() only.

> 
>>  	SDHCI_DUMP("============================================\n");
>>  }
>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>  	spin_lock_irqsave(&host->lock, flags);
>>  
>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>  		       mmc_hostname(host->mmc));
>>  		sdhci_dumpregs(host);
>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>> timer_list *t)
>>  
>>  	if (host->data || host->data_cmd ||
>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>  		       mmc_hostname(host->mmc));
>>  		sdhci_dumpregs(host);
>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>> *host, u32 intmask, u32 *intmask_p)
>>  
>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>> -		if (intmask & SDHCI_INT_TIMEOUT)
>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>  			host->cmd->error = -ETIMEDOUT;
>> -		else
>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>> +		} else {
>>  			host->cmd->error = -EILSEQ;
>> -
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>> +		}
>>  		/* Treat data command CRC error the same as data CRC error */
>>  		if (host->cmd->data &&
>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6
>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
>> +intmask, u32 *intmask_p)
>>  			  -ETIMEDOUT :
>>  			  -EILSEQ;
>>  
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>  			mrq->sbc->error = err;
>>  			__sdhci_finish_mrq(host, mrq);
>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  				host->data_cmd = NULL;
>>  				data_cmd->error = -ETIMEDOUT;
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>  				return;
>>  			}
>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>  		return;
>>  	}
>>  
>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  		host->data->error = -ETIMEDOUT;
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>> +	}
>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>  		host->data->error = -EILSEQ;
>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>> -			!= MMC_BUS_TEST_R)
>> +			!= MMC_BUS_TEST_R) {
>>  		host->data->error = -EILSEQ;
>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>> +	}
>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>  		       intmask);
>>  		sdhci_adma_show_error(host);
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>  		host->data->error = -EIO;
>>  		if (host->ops->adma_workaround)
>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 
>> @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>  	if (!host->cqe_on)
>>  		return false;
>>  
>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | 
>> +SDHCI_INT_CRC)) {
>>  		*cmd_error = -EILSEQ;
>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>> +		if (intmask & SDHCI_INT_CRC) {
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>> +		}
>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>  		*cmd_error = -ETIMEDOUT;
>> -	else
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>> +	} else
>>  		*cmd_error = 0;
>>  
>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>  		*data_error = -EILSEQ;
>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>> +		}
>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>  		*data_error = -ETIMEDOUT;
>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>  		*data_error = -EIO;
>> -	else
>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>> +	} else
>>  		*data_error = 0;
>>  
>>  	/* Clear selected interrupts. */
>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h 
>> index 7afb57c..c263f8f 100644
>> --- a/include/linux/mmc/host.h
>> +++ b/include/linux/mmc/host.h
>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>  
>>  struct mmc_host;
>>  
>> +enum mmc_err_stat {
>> +	MMC_ERR_CMD_TIMEOUT,
>> +	MMC_ERR_CMD_CRC,
>> +	MMC_ERR_DAT_TIMEOUT,
>> +	MMC_ERR_DAT_CRC,
>> +	MMC_ERR_AUTO_CMD,
>> +	MMC_ERR_ADMA,
>> +	MMC_ERR_TUNING,
>> +	MMC_ERR_CMDQ_RED,
>> +	MMC_ERR_CMDQ_GCE,
>> +	MMC_ERR_CMDQ_ICCE,
>> +	MMC_ERR_REQ_TIMEOUT,
>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>> +	MMC_ERR_ICE_CFG,
>> +	MMC_ERR_MAX,
>> +};
>> +
>>  struct mmc_host_ops {
>>  	/*
>>  	 * It is optional for the host to implement pre_req and post_req in 
>> @@ -500,6 +517,8 @@ struct mmc_host {
>>  
>>  	/* Host Software Queue support */
>>  	bool			hsq_enabled;
>> +	u32                     err_stats[MMC_ERR_MAX];
> 
> If you make it u64 then we don't have to think about the value overflowing.
> 
>>>> Sure
> 
>> +	bool			err_state;
>>  
>>  	unsigned long		private[] ____cacheline_aligned;
>>  };
>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>> DMA_FROM_DEVICE;  }
>>  
>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host 
>> +*mmc) {
>> +	mmc->err_state = true;
>> +}
>> +
>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>> +		enum mmc_err_stat stat) {
>> +
>> +	/*
>> +	 * Ignore the command timeout errors observed during
>> +	 * the card init as those are excepted.
>> +	 */
>> +	if (!mmc->err_state)
>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
> 
> This would be better handled in the card init code somewhere, not here.
> 
>>>>> Sure.
> 
>> +
>> +	mmc->err_stats[stat] += 1;
>> +}
>> +
>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>> **new_ext_csd);
>>
> 

Re: [PATCH V2] mmc: debugfs: add error statistics

[Adrian Hunter]

On 04/01/2022 17:02, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments.
> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com> 
> Sent: Monday, January 3, 2022 3:20 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
>> Hi Adrian,
>>
>> Thanks for the review.
>>
>> Please find the inline comments.
> 
> I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.
> 
>>
>> Thanks,
>> Sajida
>>
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Wednesday, December 15, 2021 7:33 PM
>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>> ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; 
>> linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; 
>> linux-kernel@vger.kernel.org
>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
>> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>
>> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>>> Add debugfs entry to query eMMC and SD card errors statistics.
>>> This feature is useful for debug and testing
>>>
>>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>>> ---
>>>
>>> Changes since V1:
>>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
>>
>> Thanks for doing this.
>>
>>> ---
>>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>>  drivers/mmc/core/queue.c   |   2 +
>>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
>>> index 3fdbc80..40210c34 100644
>>> --- a/drivers/mmc/core/debugfs.c
>>> +++ b/drivers/mmc/core/debugfs.c
>>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
>>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>>  	"%llu\n");
>>>  
>>> +static int mmc_err_state_get(void *data, u64 *val) {
>>> +	struct mmc_host *host = data;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	*val = host->err_state ? 1 : 0;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int mmc_err_state_clear(void *data, u64 val) {
>>> +	struct mmc_host *host = data;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	host->err_state = false;
>>
>> Is there much reason to disable err stats from userspace?
>>
>>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.
> 
> That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.
> 
>>>>>>> If user wants to explicitly clear then he can use this.

Seems over compilicated.  A user can just diff the old and new values:

cat /sys/kernel/debug/mmc0/err_stats > /tmp/old-stats
...later...
cat /sys/kernel/debug/mmc0/err_stats > /tmp/new-stats
diff /tmp/old-stats /tmp/new-stats
mv /tmp/new-stats /tmp/old-stats

I suggest just outputting the stats

> 
>>
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>>> +		mmc_err_state_clear, "%llu\n");
>>> +
>>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>
>> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
>>
>> 	if (!host->err_stats_enabled) {
>> 		seq_printf(file, "Not supported by driver\n");
>> 		return 0;
>> 	}
>>
>>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?
> 
> Yes, although it is not clear if this is the same as what you want from err_state, i.e. is err_state different from err_stats_enabled?
> 
>>>>>> Yes, err_state and err_stats_enabled both are different.  err_state will be set if any errors happened in driver level. 
>  err_stats_enabled will be set  if err_stats feature enabled,  if any vendor wants to use err_stats feature they will set this err_stats_enabled in their vendor specific file.
> 
>>
>>> +
>>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
>>
>> Maybe put the descriptions in an array and iterate e.g.
>>
>> 	const char *desc[MMC_ERR_MAX] = {
>> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
>> 		etc
>> 	};
>> 	int i;
>>
>> 	if (!host)
>> 		return -EINVAL;
>>
>> 	for (i = 0; i < MMC_ERR_MAX; i++) {
>> 		if (desc[i])
>> 			seq_printf(file, "# %s:\t %d\n",
>> 				   desc[1], host->err_stats[i]);
>> 	}
>>
>>>>>>>>> Sure
>>
>>> +
>>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>>> +
>>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>>> +
>>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>> +
>>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>> +
>>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_TUNING]);
>>> +
>>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>>> +
>>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>>> +
>>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>>> +
>>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int mmc_err_stats_open(struct inode *inode, struct file 
>>> +*file) {
>>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>>> +
>>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>>> +				   size_t cnt, loff_t *ppos)
>>> +{
>>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>>> +
>>> +	return cnt;
>>> +}
>>> +
>>> +static const struct file_operations mmc_err_stats_fops = {
>>> +	.open	= mmc_err_stats_open,
>>> +	.read	= seq_read,
>>> +	.write	= mmc_err_stats_write,
>>> +};
>>> +
>>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>>  	struct dentry *root;
>>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>>  				   &mmc_clock_fops);
>>>  
>>> +	debugfs_create_file("err_state", 0600, root, host,
>>> +		&mmc_err_state);
>>> +	debugfs_create_file("err_stats", 0600, root, host,
>>> +		&mmc_err_stats_fops);
>>> +
>>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>>  	if (fail_request)
>>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
>>> b15c034..5243929 100644
>>> --- a/drivers/mmc/core/queue.c
>>> +++ b/drivers/mmc/core/queue.c
>>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>>  	bool recovery_needed = false;
>>>  
>>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>>> +
>>>  	switch (issue_type) {
>>>  	case MMC_ISSUE_ASYNC:
>>>  	case MMC_ISSUE_DCMD:
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>
>> I think the core changes should be a separate patch from sdhci.
>> I would probably split into 4:
>> 	mmc core
>> 	mmc block driver
>> 	cqhci driver
>> 	sdhci driver
>>
>>>>>> Sure
>>
>>> index 07c6da1..d742051 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>>  	if (host->ops->dump_vendor_regs)
>>>  		host->ops->dump_vendor_regs(host);
>>>  
>>> +	mmc_debugfs_err_stats_enable(host->mmc);
>>
>> Why here and not in e.g. __sdhci_add_host() ?
>>
>>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.
> 
> Registers are not dumped for most errors.  Please move this to __sdhci_add_host().
> 
>>>>> err_state is true means errors happened in driver level and for most of the errors we are dumping the registers, so I am thinking it is better to have this call in sdhci_dumpregs() only.
> 
>>
>>>  	SDHCI_DUMP("============================================\n");
>>>  }
>>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>>  	spin_lock_irqsave(&host->lock, flags);
>>>  
>>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>>  		       mmc_hostname(host->mmc));
>>>  		sdhci_dumpregs(host);
>>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>>> timer_list *t)
>>>  
>>>  	if (host->data || host->data_cmd ||
>>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>>  		       mmc_hostname(host->mmc));
>>>  		sdhci_dumpregs(host);
>>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>>> *host, u32 intmask, u32 *intmask_p)
>>>  
>>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>>> -		if (intmask & SDHCI_INT_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>>  			host->cmd->error = -ETIMEDOUT;
>>> -		else
>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>> +		} else {
>>>  			host->cmd->error = -EILSEQ;
>>> -
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>> +		}
>>>  		/* Treat data command CRC error the same as data CRC error */
>>>  		if (host->cmd->data &&
>>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6
>>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
>>> +intmask, u32 *intmask_p)
>>>  			  -ETIMEDOUT :
>>>  			  -EILSEQ;
>>>  
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>>  			mrq->sbc->error = err;
>>>  			__sdhci_finish_mrq(host, mrq);
>>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  				host->data_cmd = NULL;
>>>  				data_cmd->error = -ETIMEDOUT;
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>>  				return;
>>>  			}
>>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>  		return;
>>>  	}
>>>  
>>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  		host->data->error = -ETIMEDOUT;
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>> +	}
>>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>>  		host->data->error = -EILSEQ;
>>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>>> -			!= MMC_BUS_TEST_R)
>>> +			!= MMC_BUS_TEST_R) {
>>>  		host->data->error = -EILSEQ;
>>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>> +	}
>>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>>  		       intmask);
>>>  		sdhci_adma_show_error(host);
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>  		host->data->error = -EIO;
>>>  		if (host->ops->adma_workaround)
>>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 
>>> @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>>  	if (!host->cqe_on)
>>>  		return false;
>>>  
>>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | 
>>> +SDHCI_INT_CRC)) {
>>>  		*cmd_error = -EILSEQ;
>>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_CRC) {
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>> +		}
>>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>>  		*cmd_error = -ETIMEDOUT;
>>> -	else
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>> +	} else
>>>  		*cmd_error = 0;
>>>  
>>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>>  		*data_error = -EILSEQ;
>>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>> +		}
>>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  		*data_error = -ETIMEDOUT;
>>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>  		*data_error = -EIO;
>>> -	else
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>> +	} else
>>>  		*data_error = 0;
>>>  
>>>  	/* Clear selected interrupts. */
>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h 
>>> index 7afb57c..c263f8f 100644
>>> --- a/include/linux/mmc/host.h
>>> +++ b/include/linux/mmc/host.h
>>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>>  
>>>  struct mmc_host;
>>>  
>>> +enum mmc_err_stat {
>>> +	MMC_ERR_CMD_TIMEOUT,
>>> +	MMC_ERR_CMD_CRC,
>>> +	MMC_ERR_DAT_TIMEOUT,
>>> +	MMC_ERR_DAT_CRC,
>>> +	MMC_ERR_AUTO_CMD,
>>> +	MMC_ERR_ADMA,
>>> +	MMC_ERR_TUNING,
>>> +	MMC_ERR_CMDQ_RED,
>>> +	MMC_ERR_CMDQ_GCE,
>>> +	MMC_ERR_CMDQ_ICCE,
>>> +	MMC_ERR_REQ_TIMEOUT,
>>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>>> +	MMC_ERR_ICE_CFG,
>>> +	MMC_ERR_MAX,
>>> +};
>>> +
>>>  struct mmc_host_ops {
>>>  	/*
>>>  	 * It is optional for the host to implement pre_req and post_req in 
>>> @@ -500,6 +517,8 @@ struct mmc_host {
>>>  
>>>  	/* Host Software Queue support */
>>>  	bool			hsq_enabled;
>>> +	u32                     err_stats[MMC_ERR_MAX];
>>
>> If you make it u64 then we don't have to think about the value overflowing.
>>
>>>>> Sure
>>
>>> +	bool			err_state;
>>>  
>>>  	unsigned long		private[] ____cacheline_aligned;
>>>  };
>>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>>> DMA_FROM_DEVICE;  }
>>>  
>>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host 
>>> +*mmc) {
>>> +	mmc->err_state = true;
>>> +}
>>> +
>>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>>> +		enum mmc_err_stat stat) {
>>> +
>>> +	/*
>>> +	 * Ignore the command timeout errors observed during
>>> +	 * the card init as those are excepted.
>>> +	 */
>>> +	if (!mmc->err_state)
>>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
>>
>> This would be better handled in the card init code somewhere, not here.
>>
>>>>>> Sure.
>>
>>> +
>>> +	mmc->err_stats[stat] += 1;
>>> +}
>>> +
>>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>>> **new_ext_csd);
>>>
>>
> 

RE: [PATCH V2] mmc: debugfs: add error statistics

[Sajida Bhanu (Temp) (QUIC)]

Hi Adrian,

Thanks for the review.

Please find the inline comments

Thanks,
Sajida

-----Original Message-----
From: Adrian Hunter <adrian.hunter@intel.com> 
Sent: Friday, January 7, 2022 1:13 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: Re: [PATCH V2] mmc: debugfs: add error statistics

On 04/01/2022 17:02, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments.
> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Monday, January 3, 2022 3:20 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
> ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; 
> linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; 
> linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
> nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
>> Hi Adrian,
>>
>> Thanks for the review.
>>
>> Please find the inline comments.
> 
> I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.
> 
>>
>> Thanks,
>> Sajida
>>
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Wednesday, December 15, 2021 7:33 PM
>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>> ulf.hansson@linaro.org; agross@kernel.org; 
>> bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; 
>> linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
>> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>
>> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>>> Add debugfs entry to query eMMC and SD card errors statistics.
>>> This feature is useful for debug and testing
>>>
>>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>>> ---
>>>
>>> Changes since V1:
>>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
>>
>> Thanks for doing this.
>>
>>> ---
>>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>>  drivers/mmc/core/queue.c   |   2 +
>>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
>>> index 3fdbc80..40210c34 100644
>>> --- a/drivers/mmc/core/debugfs.c
>>> +++ b/drivers/mmc/core/debugfs.c
>>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
>>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>>  	"%llu\n");
>>>  
>>> +static int mmc_err_state_get(void *data, u64 *val) {
>>> +	struct mmc_host *host = data;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	*val = host->err_state ? 1 : 0;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int mmc_err_state_clear(void *data, u64 val) {
>>> +	struct mmc_host *host = data;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	host->err_state = false;
>>
>> Is there much reason to disable err stats from userspace?
>>
>>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.
> 
> That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.
> 
>>>>>>> If user wants to explicitly clear then he can use this.

Seems over compilicated.  A user can just diff the old and new values:

cat /sys/kernel/debug/mmc0/err_stats > /tmp/old-stats ...later...
cat /sys/kernel/debug/mmc0/err_stats > /tmp/new-stats diff /tmp/old-stats /tmp/new-stats mv /tmp/new-stats /tmp/old-stats

I suggest just outputting the stats

>>>>>>> Thanks for the suggestion Adrain.
This way user has to call write to store the err_stats data to /tmp/old-stats and  user has to call read to read /tmp/old-stats.

And our idea is user call only read to get error stats info.

Please suggest me which is okay.

Thanks,
Sajida	

> 
>>
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>>> +		mmc_err_state_clear, "%llu\n");
>>> +
>>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>
>> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
>>
>> 	if (!host->err_stats_enabled) {
>> 		seq_printf(file, "Not supported by driver\n");
>> 		return 0;
>> 	}
>>
>>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?
> 
> Yes, although it is not clear if this is the same as what you want from err_state, i.e. is err_state different from err_stats_enabled?
> 
>>>>>> Yes, err_state and err_stats_enabled both are different.  err_state will be set if any errors happened in driver level. 
>  err_stats_enabled will be set  if err_stats feature enabled,  if any vendor wants to use err_stats feature they will set this err_stats_enabled in their vendor specific file.
> 
>>
>>> +
>>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
>>
>> Maybe put the descriptions in an array and iterate e.g.
>>
>> 	const char *desc[MMC_ERR_MAX] = {
>> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
>> 		etc
>> 	};
>> 	int i;
>>
>> 	if (!host)
>> 		return -EINVAL;
>>
>> 	for (i = 0; i < MMC_ERR_MAX; i++) {
>> 		if (desc[i])
>> 			seq_printf(file, "# %s:\t %d\n",
>> 				   desc[1], host->err_stats[i]);
>> 	}
>>
>>>>>>>>> Sure
>>
>>> +
>>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>>> +
>>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>>> +
>>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>> +
>>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>> +
>>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_TUNING]);
>>> +
>>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>>> +
>>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>>> +
>>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>>> +
>>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>>> +
>>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int mmc_err_stats_open(struct inode *inode, struct file
>>> +*file) {
>>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>>> +
>>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>>> +				   size_t cnt, loff_t *ppos)
>>> +{
>>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>>> +
>>> +	if (!host)
>>> +		return -EINVAL;
>>> +
>>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>>> +
>>> +	return cnt;
>>> +}
>>> +
>>> +static const struct file_operations mmc_err_stats_fops = {
>>> +	.open	= mmc_err_stats_open,
>>> +	.read	= seq_read,
>>> +	.write	= mmc_err_stats_write,
>>> +};
>>> +
>>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>>  	struct dentry *root;
>>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>>  				   &mmc_clock_fops);
>>>  
>>> +	debugfs_create_file("err_state", 0600, root, host,
>>> +		&mmc_err_state);
>>> +	debugfs_create_file("err_stats", 0600, root, host,
>>> +		&mmc_err_stats_fops);
>>> +
>>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>>  	if (fail_request)
>>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
>>> b15c034..5243929 100644
>>> --- a/drivers/mmc/core/queue.c
>>> +++ b/drivers/mmc/core/queue.c
>>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>>  	bool recovery_needed = false;
>>>  
>>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>>> +
>>>  	switch (issue_type) {
>>>  	case MMC_ISSUE_ASYNC:
>>>  	case MMC_ISSUE_DCMD:
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>
>> I think the core changes should be a separate patch from sdhci.
>> I would probably split into 4:
>> 	mmc core
>> 	mmc block driver
>> 	cqhci driver
>> 	sdhci driver
>>
>>>>>> Sure
>>
>>> index 07c6da1..d742051 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>>  	if (host->ops->dump_vendor_regs)
>>>  		host->ops->dump_vendor_regs(host);
>>>  
>>> +	mmc_debugfs_err_stats_enable(host->mmc);
>>
>> Why here and not in e.g. __sdhci_add_host() ?
>>
>>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.
> 
> Registers are not dumped for most errors.  Please move this to __sdhci_add_host().
> 
>>>>> err_state is true means errors happened in driver level and for most of the errors we are dumping the registers, so I am thinking it is better to have this call in sdhci_dumpregs() only.
> 
>>
>>>  	SDHCI_DUMP("============================================\n");
>>>  }
>>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>>  	spin_lock_irqsave(&host->lock, flags);
>>>  
>>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>>  		       mmc_hostname(host->mmc));
>>>  		sdhci_dumpregs(host);
>>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>>> timer_list *t)
>>>  
>>>  	if (host->data || host->data_cmd ||
>>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>>  		       mmc_hostname(host->mmc));
>>>  		sdhci_dumpregs(host);
>>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>>> *host, u32 intmask, u32 *intmask_p)
>>>  
>>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>>> -		if (intmask & SDHCI_INT_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>>  			host->cmd->error = -ETIMEDOUT;
>>> -		else
>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>> +		} else {
>>>  			host->cmd->error = -EILSEQ;
>>> -
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>> +		}
>>>  		/* Treat data command CRC error the same as data CRC error */
>>>  		if (host->cmd->data &&
>>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6
>>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
>>> +intmask, u32 *intmask_p)
>>>  			  -ETIMEDOUT :
>>>  			  -EILSEQ;
>>>  
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>>  			mrq->sbc->error = err;
>>>  			__sdhci_finish_mrq(host, mrq);
>>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  				host->data_cmd = NULL;
>>>  				data_cmd->error = -ETIMEDOUT;
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>>  				return;
>>>  			}
>>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>  		return;
>>>  	}
>>>  
>>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  		host->data->error = -ETIMEDOUT;
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>> +	}
>>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>>  		host->data->error = -EILSEQ;
>>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>>> -			!= MMC_BUS_TEST_R)
>>> +			!= MMC_BUS_TEST_R) {
>>>  		host->data->error = -EILSEQ;
>>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>> +	}
>>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>>  		       intmask);
>>>  		sdhci_adma_show_error(host);
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>  		host->data->error = -EIO;
>>>  		if (host->ops->adma_workaround)
>>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 
>>> @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>>  	if (!host->cqe_on)
>>>  		return false;
>>>  
>>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT |
>>> +SDHCI_INT_CRC)) {
>>>  		*cmd_error = -EILSEQ;
>>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_CRC) {
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>> +		}
>>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>>  		*cmd_error = -ETIMEDOUT;
>>> -	else
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>> +	} else
>>>  		*cmd_error = 0;
>>>  
>>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>>  		*data_error = -EILSEQ;
>>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>> +		}
>>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>  		*data_error = -ETIMEDOUT;
>>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>  		*data_error = -EIO;
>>> -	else
>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>> +	} else
>>>  		*data_error = 0;
>>>  
>>>  	/* Clear selected interrupts. */
>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h 
>>> index 7afb57c..c263f8f 100644
>>> --- a/include/linux/mmc/host.h
>>> +++ b/include/linux/mmc/host.h
>>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>>  
>>>  struct mmc_host;
>>>  
>>> +enum mmc_err_stat {
>>> +	MMC_ERR_CMD_TIMEOUT,
>>> +	MMC_ERR_CMD_CRC,
>>> +	MMC_ERR_DAT_TIMEOUT,
>>> +	MMC_ERR_DAT_CRC,
>>> +	MMC_ERR_AUTO_CMD,
>>> +	MMC_ERR_ADMA,
>>> +	MMC_ERR_TUNING,
>>> +	MMC_ERR_CMDQ_RED,
>>> +	MMC_ERR_CMDQ_GCE,
>>> +	MMC_ERR_CMDQ_ICCE,
>>> +	MMC_ERR_REQ_TIMEOUT,
>>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>>> +	MMC_ERR_ICE_CFG,
>>> +	MMC_ERR_MAX,
>>> +};
>>> +
>>>  struct mmc_host_ops {
>>>  	/*
>>>  	 * It is optional for the host to implement pre_req and post_req 
>>> in @@ -500,6 +517,8 @@ struct mmc_host {
>>>  
>>>  	/* Host Software Queue support */
>>>  	bool			hsq_enabled;
>>> +	u32                     err_stats[MMC_ERR_MAX];
>>
>> If you make it u64 then we don't have to think about the value overflowing.
>>
>>>>> Sure
>>
>>> +	bool			err_state;
>>>  
>>>  	unsigned long		private[] ____cacheline_aligned;
>>>  };
>>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>>> DMA_FROM_DEVICE;  }
>>>  
>>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host
>>> +*mmc) {
>>> +	mmc->err_state = true;
>>> +}
>>> +
>>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>>> +		enum mmc_err_stat stat) {
>>> +
>>> +	/*
>>> +	 * Ignore the command timeout errors observed during
>>> +	 * the card init as those are excepted.
>>> +	 */
>>> +	if (!mmc->err_state)
>>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
>>
>> This would be better handled in the card init code somewhere, not here.
>>
>>>>>> Sure.
>>
>>> +
>>> +	mmc->err_stats[stat] += 1;
>>> +}
>>> +
>>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>>> **new_ext_csd);
>>>
>>
> 

Re: [PATCH V2] mmc: debugfs: add error statistics

[Adrian Hunter]

On 10/01/2022 15:11, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments
> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com> 
> Sent: Friday, January 7, 2022 1:13 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 04/01/2022 17:02, Sajida Bhanu (Temp) (QUIC) wrote:
>> Hi Adrian,
>>
>> Thanks for the review.
>>
>> Please find the inline comments.
>>
>> Thanks,
>> Sajida
>>
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Monday, January 3, 2022 3:20 PM
>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>> ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; 
>> linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; 
>> linux-kernel@vger.kernel.org
>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
>> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>
>> On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
>>> Hi Adrian,
>>>
>>> Thanks for the review.
>>>
>>> Please find the inline comments.
>>
>> I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.
>>
>>>
>>> Thanks,
>>> Sajida
>>>
>>> -----Original Message-----
>>> From: Adrian Hunter <adrian.hunter@intel.com>
>>> Sent: Wednesday, December 15, 2021 7:33 PM
>>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>>> ulf.hansson@linaro.org; agross@kernel.org; 
>>> bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; 
>>> linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
>>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
>>> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>>
>>> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>>>> Add debugfs entry to query eMMC and SD card errors statistics.
>>>> This feature is useful for debug and testing
>>>>
>>>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>>>> ---
>>>>
>>>> Changes since V1:
>>>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>>>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
>>>
>>> Thanks for doing this.
>>>
>>>> ---
>>>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>>>  drivers/mmc/core/queue.c   |   2 +
>>>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c 
>>>> index 3fdbc80..40210c34 100644
>>>> --- a/drivers/mmc/core/debugfs.c
>>>> +++ b/drivers/mmc/core/debugfs.c
>>>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
>>>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>>>  	"%llu\n");
>>>>  
>>>> +static int mmc_err_state_get(void *data, u64 *val) {
>>>> +	struct mmc_host *host = data;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	*val = host->err_state ? 1 : 0;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int mmc_err_state_clear(void *data, u64 val) {
>>>> +	struct mmc_host *host = data;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	host->err_state = false;
>>>
>>> Is there much reason to disable err stats from userspace?
>>>
>>>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.
>>
>> That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.
>>
>>>>>>>> If user wants to explicitly clear then he can use this.
> 
> Seems over compilicated.  A user can just diff the old and new values:
> 
> cat /sys/kernel/debug/mmc0/err_stats > /tmp/old-stats ...later...
> cat /sys/kernel/debug/mmc0/err_stats > /tmp/new-stats diff /tmp/old-stats /tmp/new-stats mv /tmp/new-stats /tmp/old-stats
> 
> I suggest just outputting the stats
> 
>>>>>>>> Thanks for the suggestion Adrain.
> This way user has to call write to store the err_stats data to /tmp/old-stats and  user has to call read to read /tmp/old-stats.

Only if you need to see what has changed

> 
> And our idea is user call only read to get error stats info.
> 
> Please suggest me which is okay.

Please let's start with just outputting the stats.

> 
> Thanks,
> Sajida	
> 
>>
>>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>>>> +		mmc_err_state_clear, "%llu\n");
>>>> +
>>>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>>>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>
>>> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
>>>
>>> 	if (!host->err_stats_enabled) {
>>> 		seq_printf(file, "Not supported by driver\n");
>>> 		return 0;
>>> 	}
>>>
>>>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?
>>
>> Yes, although it is not clear if this is the same as what you want from err_state, i.e. is err_state different from err_stats_enabled?
>>
>>>>>>> Yes, err_state and err_stats_enabled both are different.  err_state will be set if any errors happened in driver level. 
>>  err_stats_enabled will be set  if err_stats feature enabled,  if any vendor wants to use err_stats feature they will set this err_stats_enabled in their vendor specific file.
>>
>>>
>>>> +
>>>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
>>>
>>> Maybe put the descriptions in an array and iterate e.g.
>>>
>>> 	const char *desc[MMC_ERR_MAX] = {
>>> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
>>> 		etc
>>> 	};
>>> 	int i;
>>>
>>> 	if (!host)
>>> 		return -EINVAL;
>>>
>>> 	for (i = 0; i < MMC_ERR_MAX; i++) {
>>> 		if (desc[i])
>>> 			seq_printf(file, "# %s:\t %d\n",
>>> 				   desc[1], host->err_stats[i]);
>>> 	}
>>>
>>>>>>>>>> Sure
>>>
>>>> +
>>>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>>>> +
>>>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>>>> +
>>>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>>> +
>>>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>>> +
>>>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_TUNING]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>>>> +
>>>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int mmc_err_stats_open(struct inode *inode, struct file
>>>> +*file) {
>>>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>>>> +
>>>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>>>> +				   size_t cnt, loff_t *ppos)
>>>> +{
>>>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>>>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>>>> +
>>>> +	return cnt;
>>>> +}
>>>> +
>>>> +static const struct file_operations mmc_err_stats_fops = {
>>>> +	.open	= mmc_err_stats_open,
>>>> +	.read	= seq_read,
>>>> +	.write	= mmc_err_stats_write,
>>>> +};
>>>> +
>>>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>>>  	struct dentry *root;
>>>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>>>  				   &mmc_clock_fops);
>>>>  
>>>> +	debugfs_create_file("err_state", 0600, root, host,
>>>> +		&mmc_err_state);
>>>> +	debugfs_create_file("err_stats", 0600, root, host,
>>>> +		&mmc_err_stats_fops);
>>>> +
>>>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>>>  	if (fail_request)
>>>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>>>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
>>>> b15c034..5243929 100644
>>>> --- a/drivers/mmc/core/queue.c
>>>> +++ b/drivers/mmc/core/queue.c
>>>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>>>  	bool recovery_needed = false;
>>>>  
>>>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>>>> +
>>>>  	switch (issue_type) {
>>>>  	case MMC_ISSUE_ASYNC:
>>>>  	case MMC_ISSUE_DCMD:
>>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>>
>>> I think the core changes should be a separate patch from sdhci.
>>> I would probably split into 4:
>>> 	mmc core
>>> 	mmc block driver
>>> 	cqhci driver
>>> 	sdhci driver
>>>
>>>>>>> Sure
>>>
>>>> index 07c6da1..d742051 100644
>>>> --- a/drivers/mmc/host/sdhci.c
>>>> +++ b/drivers/mmc/host/sdhci.c
>>>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>>>  	if (host->ops->dump_vendor_regs)
>>>>  		host->ops->dump_vendor_regs(host);
>>>>  
>>>> +	mmc_debugfs_err_stats_enable(host->mmc);
>>>
>>> Why here and not in e.g. __sdhci_add_host() ?
>>>
>>>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.
>>
>> Registers are not dumped for most errors.  Please move this to __sdhci_add_host().
>>
>>>>>> err_state is true means errors happened in driver level and for most of the errors we are dumping the registers, so I am thinking it is better to have this call in sdhci_dumpregs() only.
>>
>>>
>>>>  	SDHCI_DUMP("============================================\n");
>>>>  }
>>>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>>>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>>>  	spin_lock_irqsave(&host->lock, flags);
>>>>  
>>>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>>>  		       mmc_hostname(host->mmc));
>>>>  		sdhci_dumpregs(host);
>>>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>>>> timer_list *t)
>>>>  
>>>>  	if (host->data || host->data_cmd ||
>>>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>>>  		       mmc_hostname(host->mmc));
>>>>  		sdhci_dumpregs(host);
>>>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>>>> *host, u32 intmask, u32 *intmask_p)
>>>>  
>>>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>>>> -		if (intmask & SDHCI_INT_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>>>  			host->cmd->error = -ETIMEDOUT;
>>>> -		else
>>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>> +		} else {
>>>>  			host->cmd->error = -EILSEQ;
>>>> -
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>>> +		}
>>>>  		/* Treat data command CRC error the same as data CRC error */
>>>>  		if (host->cmd->data &&
>>>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ -3266,6
>>>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
>>>> +intmask, u32 *intmask_p)
>>>>  			  -ETIMEDOUT :
>>>>  			  -EILSEQ;
>>>>  
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>>>  			mrq->sbc->error = err;
>>>>  			__sdhci_finish_mrq(host, mrq);
>>>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  				host->data_cmd = NULL;
>>>>  				data_cmd->error = -ETIMEDOUT;
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>>>  				return;
>>>>  			}
>>>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>>  		return;
>>>>  	}
>>>>  
>>>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  		host->data->error = -ETIMEDOUT;
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>>> +	}
>>>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>>>  		host->data->error = -EILSEQ;
>>>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>>>> -			!= MMC_BUS_TEST_R)
>>>> +			!= MMC_BUS_TEST_R) {
>>>>  		host->data->error = -EILSEQ;
>>>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>>> +	}
>>>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>>>  		       intmask);
>>>>  		sdhci_adma_show_error(host);
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>>  		host->data->error = -EIO;
>>>>  		if (host->ops->adma_workaround)
>>>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 
>>>> @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>>>  	if (!host->cqe_on)
>>>>  		return false;
>>>>  
>>>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>>>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT |
>>>> +SDHCI_INT_CRC)) {
>>>>  		*cmd_error = -EILSEQ;
>>>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_CRC) {
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>>> +		}
>>>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>>>  		*cmd_error = -ETIMEDOUT;
>>>> -	else
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>> +	} else
>>>>  		*cmd_error = 0;
>>>>  
>>>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>>>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>>>  		*data_error = -EILSEQ;
>>>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>>> +		}
>>>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  		*data_error = -ETIMEDOUT;
>>>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>>  		*data_error = -EIO;
>>>> -	else
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>> +	} else
>>>>  		*data_error = 0;
>>>>  
>>>>  	/* Clear selected interrupts. */
>>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h 
>>>> index 7afb57c..c263f8f 100644
>>>> --- a/include/linux/mmc/host.h
>>>> +++ b/include/linux/mmc/host.h
>>>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>>>  
>>>>  struct mmc_host;
>>>>  
>>>> +enum mmc_err_stat {
>>>> +	MMC_ERR_CMD_TIMEOUT,
>>>> +	MMC_ERR_CMD_CRC,
>>>> +	MMC_ERR_DAT_TIMEOUT,
>>>> +	MMC_ERR_DAT_CRC,
>>>> +	MMC_ERR_AUTO_CMD,
>>>> +	MMC_ERR_ADMA,
>>>> +	MMC_ERR_TUNING,
>>>> +	MMC_ERR_CMDQ_RED,
>>>> +	MMC_ERR_CMDQ_GCE,
>>>> +	MMC_ERR_CMDQ_ICCE,
>>>> +	MMC_ERR_REQ_TIMEOUT,
>>>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>>>> +	MMC_ERR_ICE_CFG,
>>>> +	MMC_ERR_MAX,
>>>> +};
>>>> +
>>>>  struct mmc_host_ops {
>>>>  	/*
>>>>  	 * It is optional for the host to implement pre_req and post_req 
>>>> in @@ -500,6 +517,8 @@ struct mmc_host {
>>>>  
>>>>  	/* Host Software Queue support */
>>>>  	bool			hsq_enabled;
>>>> +	u32                     err_stats[MMC_ERR_MAX];
>>>
>>> If you make it u64 then we don't have to think about the value overflowing.
>>>
>>>>>> Sure
>>>
>>>> +	bool			err_state;
>>>>  
>>>>  	unsigned long		private[] ____cacheline_aligned;
>>>>  };
>>>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>>>> DMA_FROM_DEVICE;  }
>>>>  
>>>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host
>>>> +*mmc) {
>>>> +	mmc->err_state = true;
>>>> +}
>>>> +
>>>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>>>> +		enum mmc_err_stat stat) {
>>>> +
>>>> +	/*
>>>> +	 * Ignore the command timeout errors observed during
>>>> +	 * the card init as those are excepted.
>>>> +	 */
>>>> +	if (!mmc->err_state)
>>>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
>>>
>>> This would be better handled in the card init code somewhere, not here.
>>>
>>>>>>> Sure.
>>>
>>>> +
>>>> +	mmc->err_stats[stat] += 1;
>>>> +}
>>>> +
>>>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>>>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>>>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>>>> **new_ext_csd);
>>>>
>>>
>>
> 

RE: [PATCH V2] mmc: debugfs: add error statistics

[Sajida Bhanu (Temp) (QUIC)]

-----Original Message-----
From: Adrian Hunter <adrian.hunter@intel.com> 
Sent: Monday, January 10, 2022 6:59 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org
Subject: Re: [PATCH V2] mmc: debugfs: add error statistics

On 10/01/2022 15:11, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi Adrian,
> 
> Thanks for the review.
> 
> Please find the inline comments
> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Friday, January 7, 2022 1:13 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
> ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; 
> linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; 
> linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
> nitirawa@codeaurora.org; sayalil@codeaurora.org
> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
> 
> On 04/01/2022 17:02, Sajida Bhanu (Temp) (QUIC) wrote:
>> Hi Adrian,
>>
>> Thanks for the review.
>>
>> Please find the inline comments.
>>
>> Thanks,
>> Sajida
>>
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Monday, January 3, 2022 3:20 PM
>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>> ulf.hansson@linaro.org; agross@kernel.org; 
>> bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; 
>> linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) 
>> <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>
>> On 21/12/2021 09:16, Sajida Bhanu (Temp) (QUIC) wrote:
>>> Hi Adrian,
>>>
>>> Thanks for the review.
>>>
>>> Please find the inline comments.
>>
>> I find the way the inline comments are done a bit difficult to follow, since what I wrote is not quoted, and what you wrote is quoted.  Normally it is the other way around.
>>
>>>
>>> Thanks,
>>> Sajida
>>>
>>> -----Original Message-----
>>> From: Adrian Hunter <adrian.hunter@intel.com>
>>> Sent: Wednesday, December 15, 2021 7:33 PM
>>> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; 
>>> riteshh@codeaurora.org; Asutosh Das (asd) <asutoshd@quicinc.com>; 
>>> ulf.hansson@linaro.org; agross@kernel.org; 
>>> bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; 
>>> linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
>>> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash 
>>> Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati 
>>> (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; 
>>> nitirawa@codeaurora.org; sayalil@codeaurora.org
>>> Subject: Re: [PATCH V2] mmc: debugfs: add error statistics
>>>
>>> On 14/12/2021 16:41, Shaik Sajida Bhanu wrote:
>>>> Add debugfs entry to query eMMC and SD card errors statistics.
>>>> This feature is useful for debug and testing
>>>>
>>>> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
>>>> ---
>>>>
>>>> Changes since V1:
>>>> 	-Removed sysfs entry for eMMC and SD card error statistics and added
>>>> 	 debugfs entry as suggested by Adrian Hunter and Ulf Hansson.
>>>
>>> Thanks for doing this.
>>>
>>>> ---
>>>>  drivers/mmc/core/debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>>>>  drivers/mmc/core/queue.c   |   2 +
>>>>  drivers/mmc/host/sdhci.c   |  53 ++++++++++++++++++-----
>>>>  include/linux/mmc/host.h   |  37 ++++++++++++++++
>>>>  4 files changed, 186 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/core/debugfs.c 
>>>> b/drivers/mmc/core/debugfs.c index 3fdbc80..40210c34 100644
>>>> --- a/drivers/mmc/core/debugfs.c
>>>> +++ b/drivers/mmc/core/debugfs.c
>>>> @@ -223,6 +223,107 @@ static int mmc_clock_opt_set(void *data, u64
>>>> val)  DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
>>>>  	"%llu\n");
>>>>  
>>>> +static int mmc_err_state_get(void *data, u64 *val) {
>>>> +	struct mmc_host *host = data;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	*val = host->err_state ? 1 : 0;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int mmc_err_state_clear(void *data, u64 val) {
>>>> +	struct mmc_host *host = data;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	host->err_state = false;
>>>
>>> Is there much reason to disable err stats from userspace?
>>>
>>>>>>>> Yes , while debugging we can go and check err_state , It is false means no errors happened in driver level and true means errors happened in driver level and then we can go and check err_stats[] to know more on error details like data CRC , command CRC etc.
>>
>> That is not exectly how it is programmed.  "err_state is false" means no errors have been recorded, not that no errors happended.
>>
>>>>>>>> If user wants to explicitly clear then he can use this.
> 
> Seems over compilicated.  A user can just diff the old and new values:
> 
> cat /sys/kernel/debug/mmc0/err_stats > /tmp/old-stats ...later...
> cat /sys/kernel/debug/mmc0/err_stats > /tmp/new-stats diff 
> /tmp/old-stats /tmp/new-stats mv /tmp/new-stats /tmp/old-stats
> 
> I suggest just outputting the stats
> 
>>>>>>>> Thanks for the suggestion Adrain.
> This way user has to call write to store the err_stats data to /tmp/old-stats and  user has to call read to read /tmp/old-stats.

Only if you need to see what has changed

> 
> And our idea is user call only read to get error stats info.
> 
> Please suggest me which is okay.

Please let's start with just outputting the stats.

>>>>> Sure. Thanks for the suggestion.
> 
> Thanks,
> Sajida	
> 
>>
>>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get,
>>>> +		mmc_err_state_clear, "%llu\n");
>>>> +
>>>> +static int mmc_err_stats_show(struct seq_file *file, void *data) {
>>>> +	struct mmc_host *host = (struct mmc_host *)file->private;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>
>>> I was thinking we needed a way to determine whether stats were being collected because not all drivers would support it at least initially e.g.
>>>
>>> 	if (!host->err_stats_enabled) {
>>> 		seq_printf(file, "Not supported by driver\n");
>>> 		return 0;
>>> 	}
>>>
>>>>>>>>>> You mean declare another variable (err_stats_enabled) and enable it in probe?
>>
>> Yes, although it is not clear if this is the same as what you want from err_state, i.e. is err_state different from err_stats_enabled?
>>
>>>>>>> Yes, err_state and err_stats_enabled both are different.  err_state will be set if any errors happened in driver level. 
>>  err_stats_enabled will be set  if err_stats feature enabled,  if any vendor wants to use err_stats feature they will set this err_stats_enabled in their vendor specific file.
>>
>>>
>>>> +
>>>> +	seq_printf(file, "# Command Timeout Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMD_TIMEOUT]);
>>>
>>> Maybe put the descriptions in an array and iterate e.g.
>>>
>>> 	const char *desc[MMC_ERR_MAX] = {
>>> 		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
>>> 		etc
>>> 	};
>>> 	int i;
>>>
>>> 	if (!host)
>>> 		return -EINVAL;
>>>
>>> 	for (i = 0; i < MMC_ERR_MAX; i++) {
>>> 		if (desc[i])
>>> 			seq_printf(file, "# %s:\t %d\n",
>>> 				   desc[1], host->err_stats[i]);
>>> 	}
>>>
>>>>>>>>>> Sure
>>>
>>>> +
>>>> +	seq_printf(file, "# Command CRC Errors Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMD_CRC]);
>>>> +
>>>> +	seq_printf(file, "# Data Timeout Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_DAT_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# Data CRC Errors Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_DAT_CRC]);
>>>> +
>>>> +	seq_printf(file, "# Auto-Cmd Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>>> +
>>>> +	seq_printf(file, "# ADMA Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ADMA]);
>>>> +
>>>> +	seq_printf(file, "# Tuning Error Occurred:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_TUNING]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ RED Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_RED]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ GCE Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_GCE]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ ICCE Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_ICCE]);
>>>> +
>>>> +	seq_printf(file, "# Request Timedout:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_REQ_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# CMDQ Request Timedout:\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_CMDQ_REQ_TIMEOUT]);
>>>> +
>>>> +	seq_printf(file, "# ICE Config Errors:\t\t %d\n",
>>>> +		   host->err_stats[MMC_ERR_ICE_CFG]);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int mmc_err_stats_open(struct inode *inode, struct file
>>>> +*file) {
>>>> +	return single_open(file, mmc_err_stats_show, inode->i_private); }
>>>> +
>>>> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
>>>> +				   size_t cnt, loff_t *ppos)
>>>> +{
>>>> +	struct mmc_host *host = filp->f_mapping->host->i_private;
>>>> +
>>>> +	if (!host)
>>>> +		return -EINVAL;
>>>> +
>>>> +	pr_debug("%s: Resetting MMC error statistics\n", __func__);
>>>> +	memset(host->err_stats, 0, sizeof(host->err_stats));
>>>> +
>>>> +	return cnt;
>>>> +}
>>>> +
>>>> +static const struct file_operations mmc_err_stats_fops = {
>>>> +	.open	= mmc_err_stats_open,
>>>> +	.read	= seq_read,
>>>> +	.write	= mmc_err_stats_write,
>>>> +};
>>>> +
>>>>  void mmc_add_host_debugfs(struct mmc_host *host)  {
>>>>  	struct dentry *root;
>>>> @@ -236,6 +337,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
>>>>  	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
>>>>  				   &mmc_clock_fops);
>>>>  
>>>> +	debugfs_create_file("err_state", 0600, root, host,
>>>> +		&mmc_err_state);
>>>> +	debugfs_create_file("err_stats", 0600, root, host,
>>>> +		&mmc_err_stats_fops);
>>>> +
>>>>  #ifdef CONFIG_FAIL_MMC_REQUEST
>>>>  	if (fail_request)
>>>>  		setup_fault_attr(&fail_default_attr, fail_request); diff --git 
>>>> a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index
>>>> b15c034..5243929 100644
>>>> --- a/drivers/mmc/core/queue.c
>>>> +++ b/drivers/mmc/core/queue.c
>>>> @@ -100,6 +100,8 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
>>>>  	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
>>>>  	bool recovery_needed = false;
>>>>  
>>>> +	mmc_debugfs_err_stats_inc(host, MMC_ERR_CMDQ_REQ_TIMEOUT);
>>>> +
>>>>  	switch (issue_type) {
>>>>  	case MMC_ISSUE_ASYNC:
>>>>  	case MMC_ISSUE_DCMD:
>>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>>
>>> I think the core changes should be a separate patch from sdhci.
>>> I would probably split into 4:
>>> 	mmc core
>>> 	mmc block driver
>>> 	cqhci driver
>>> 	sdhci driver
>>>
>>>>>>> Sure
>>>
>>>> index 07c6da1..d742051 100644
>>>> --- a/drivers/mmc/host/sdhci.c
>>>> +++ b/drivers/mmc/host/sdhci.c
>>>> @@ -113,6 +113,7 @@ void sdhci_dumpregs(struct sdhci_host *host)
>>>>  	if (host->ops->dump_vendor_regs)
>>>>  		host->ops->dump_vendor_regs(host);
>>>>  
>>>> +	mmc_debugfs_err_stats_enable(host->mmc);
>>>
>>> Why here and not in e.g. __sdhci_add_host() ?
>>>
>>>>>>> If any errors happened  in driver level then we will call sdhci_dumpregs() right( err_state true means some errors happened in driver level ).  So it is better to call mmc_debugfs_err_stats_enable() here.
>>
>> Registers are not dumped for most errors.  Please move this to __sdhci_add_host().
>>
>>>>>> err_state is true means errors happened in driver level and for most of the errors we are dumping the registers, so I am thinking it is better to have this call in sdhci_dumpregs() only.
>>
>>>
>>>>  	SDHCI_DUMP("============================================\n");
>>>>  }
>>>>  EXPORT_SYMBOL_GPL(sdhci_dumpregs);
>>>> @@ -3159,6 +3160,7 @@ static void sdhci_timeout_timer(struct timer_list *t)
>>>>  	spin_lock_irqsave(&host->lock, flags);
>>>>  
>>>>  	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>>  		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
>>>>  		       mmc_hostname(host->mmc));
>>>>  		sdhci_dumpregs(host);
>>>> @@ -3181,6 +3183,7 @@ static void sdhci_timeout_data_timer(struct 
>>>> timer_list *t)
>>>>  
>>>>  	if (host->data || host->data_cmd ||
>>>>  	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_REQ_TIMEOUT);
>>>>  		pr_err("%s: Timeout waiting for hardware interrupt.\n",
>>>>  		       mmc_hostname(host->mmc));
>>>>  		sdhci_dumpregs(host);
>>>> @@ -3240,11 +3243,15 @@ static void sdhci_cmd_irq(struct sdhci_host 
>>>> *host, u32 intmask, u32 *intmask_p)
>>>>  
>>>>  	if (intmask & (SDHCI_INT_TIMEOUT | SDHCI_INT_CRC |
>>>>  		       SDHCI_INT_END_BIT | SDHCI_INT_INDEX)) {
>>>> -		if (intmask & SDHCI_INT_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_TIMEOUT) {
>>>>  			host->cmd->error = -ETIMEDOUT;
>>>> -		else
>>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>> +		} else {
>>>>  			host->cmd->error = -EILSEQ;
>>>> -
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>>> +		}
>>>>  		/* Treat data command CRC error the same as data CRC error */
>>>>  		if (host->cmd->data &&
>>>>  		    (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == @@ 
>>>> -3266,6
>>>> +3273,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 
>>>> +intmask, u32 *intmask_p)
>>>>  			  -ETIMEDOUT :
>>>>  			  -EILSEQ;
>>>>  
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_AUTO_CMD);
>>>>  		if (sdhci_auto_cmd23(host, mrq)) {
>>>>  			mrq->sbc->error = err;
>>>>  			__sdhci_finish_mrq(host, mrq);
>>>> @@ -3342,6 +3350,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>>  			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  				host->data_cmd = NULL;
>>>>  				data_cmd->error = -ETIMEDOUT;
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>>  				__sdhci_finish_mrq(host, data_cmd->mrq);
>>>>  				return;
>>>>  			}
>>>> @@ -3375,18 +3384,25 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>>>>  		return;
>>>>  	}
>>>>  
>>>> -	if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>>> +	if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  		host->data->error = -ETIMEDOUT;
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>>> +	}
>>>>  	else if (intmask & SDHCI_INT_DATA_END_BIT)
>>>>  		host->data->error = -EILSEQ;
>>>>  	else if ((intmask & SDHCI_INT_DATA_CRC) &&
>>>>  		SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
>>>> -			!= MMC_BUS_TEST_R)
>>>> +			!= MMC_BUS_TEST_R) {
>>>>  		host->data->error = -EILSEQ;
>>>> +		if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +				host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +			mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>>> +	}
>>>>  	else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>>  		pr_err("%s: ADMA error: 0x%08x\n", mmc_hostname(host->mmc),
>>>>  		       intmask);
>>>>  		sdhci_adma_show_error(host);
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>>  		host->data->error = -EIO;
>>>>  		if (host->ops->adma_workaround)
>>>>  			host->ops->adma_workaround(host, intmask); @@ -3905,20 +3921,33 
>>>> @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>>>>  	if (!host->cqe_on)
>>>>  		return false;
>>>>  
>>>> -	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC))
>>>> +	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT |
>>>> +SDHCI_INT_CRC)) {
>>>>  		*cmd_error = -EILSEQ;
>>>> -	else if (intmask & SDHCI_INT_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_CRC) {
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_CRC);
>>>> +		}
>>>> +	} else if (intmask & SDHCI_INT_TIMEOUT) {
>>>>  		*cmd_error = -ETIMEDOUT;
>>>> -	else
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_CMD_TIMEOUT);
>>>> +	} else
>>>>  		*cmd_error = 0;
>>>>  
>>>> -	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC))
>>>> +	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>>>>  		*data_error = -EILSEQ;
>>>> -	else if (intmask & SDHCI_INT_DATA_TIMEOUT)
>>>> +		if (intmask & SDHCI_INT_DATA_CRC) {
>>>> +			if (host->cmd->opcode != MMC_SEND_TUNING_BLOCK ||
>>>> +					host->cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
>>>> +				mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_CRC);
>>>> +		}
>>>> +	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>>>>  		*data_error = -ETIMEDOUT;
>>>> -	else if (intmask & SDHCI_INT_ADMA_ERROR)
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_DAT_TIMEOUT);
>>>> +	} else if (intmask & SDHCI_INT_ADMA_ERROR) {
>>>>  		*data_error = -EIO;
>>>> -	else
>>>> +		mmc_debugfs_err_stats_inc(host->mmc, MMC_ERR_ADMA);
>>>> +	} else
>>>>  		*data_error = 0;
>>>>  
>>>>  	/* Clear selected interrupts. */
>>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h 
>>>> index 7afb57c..c263f8f 100644
>>>> --- a/include/linux/mmc/host.h
>>>> +++ b/include/linux/mmc/host.h
>>>> @@ -93,6 +93,23 @@ struct mmc_clk_phase_map {
>>>>  
>>>>  struct mmc_host;
>>>>  
>>>> +enum mmc_err_stat {
>>>> +	MMC_ERR_CMD_TIMEOUT,
>>>> +	MMC_ERR_CMD_CRC,
>>>> +	MMC_ERR_DAT_TIMEOUT,
>>>> +	MMC_ERR_DAT_CRC,
>>>> +	MMC_ERR_AUTO_CMD,
>>>> +	MMC_ERR_ADMA,
>>>> +	MMC_ERR_TUNING,
>>>> +	MMC_ERR_CMDQ_RED,
>>>> +	MMC_ERR_CMDQ_GCE,
>>>> +	MMC_ERR_CMDQ_ICCE,
>>>> +	MMC_ERR_REQ_TIMEOUT,
>>>> +	MMC_ERR_CMDQ_REQ_TIMEOUT,
>>>> +	MMC_ERR_ICE_CFG,
>>>> +	MMC_ERR_MAX,
>>>> +};
>>>> +
>>>>  struct mmc_host_ops {
>>>>  	/*
>>>>  	 * It is optional for the host to implement pre_req and post_req 
>>>> in @@ -500,6 +517,8 @@ struct mmc_host {
>>>>  
>>>>  	/* Host Software Queue support */
>>>>  	bool			hsq_enabled;
>>>> +	u32                     err_stats[MMC_ERR_MAX];
>>>
>>> If you make it u64 then we don't have to think about the value overflowing.
>>>
>>>>>> Sure
>>>
>>>> +	bool			err_state;
>>>>  
>>>>  	unsigned long		private[] ____cacheline_aligned;
>>>>  };
>>>> @@ -635,6 +654,24 @@ static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
>>>>  	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : 
>>>> DMA_FROM_DEVICE;  }
>>>>  
>>>> +static inline void mmc_debugfs_err_stats_enable(struct mmc_host
>>>> +*mmc) {
>>>> +	mmc->err_state = true;
>>>> +}
>>>> +
>>>> +static inline void mmc_debugfs_err_stats_inc(struct mmc_host *mmc,
>>>> +		enum mmc_err_stat stat) {
>>>> +
>>>> +	/*
>>>> +	 * Ignore the command timeout errors observed during
>>>> +	 * the card init as those are excepted.
>>>> +	 */
>>>> +	if (!mmc->err_state)
>>>> +		mmc->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
>>>
>>> This would be better handled in the card init code somewhere, not here.
>>>
>>>>>>> Sure.
>>>
>>>> +
>>>> +	mmc->err_stats[stat] += 1;
>>>> +}
>>>> +
>>>>  int mmc_send_tuning(struct mmc_host *host, u32 opcode, int 
>>>> *cmd_error);  int mmc_send_abort_tuning(struct mmc_host *host, u32 
>>>> opcode);  int mmc_get_ext_csd(struct mmc_card *card, u8 
>>>> **new_ext_csd);
>>>>
>>>
>>
>