[PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch series adds busy detect for stm32 sdmmc variant.
Some adaptations are required:
-Avoid to check and poll busy status when is not expected.
-Clear busy status bit if busy_detect_flag and busy_detect_mask are
 different.
-Add hardware busy timeout with MMCIDATATIMER register.

V2:
-mmci_cmd_irq cleanup in separate patch.
-simplify the busy_detect_flag exclude
-replace sdmmc specific comment in
"mmc: mmci: avoid fake busy polling in mmci_irq"
to focus on common behavior

Ludovic Barre (5):
  mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
  mmc: mmci: avoid fake busy polling in mmci_irq
  mmc: mmci: fix clear of busy detect status
  mmc: mmci: add hardware busy timeout feature
  mmc: mmci: add busy detect for stm32 sdmmc variant

 drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
 drivers/mmc/host/mmci.h |  3 +++
 2 files changed, 51 insertions(+), 13 deletions(-)

-- 
2.7.4

[PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch series adds busy detect for stm32 sdmmc variant.
Some adaptations are required:
-Avoid to check and poll busy status when is not expected.
-Clear busy status bit if busy_detect_flag and busy_detect_mask are
 different.
-Add hardware busy timeout with MMCIDATATIMER register.

V2:
-mmci_cmd_irq cleanup in separate patch.
-simplify the busy_detect_flag exclude
-replace sdmmc specific comment in
"mmc: mmci: avoid fake busy polling in mmci_irq"
to focus on common behavior

Ludovic Barre (5):
  mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
  mmc: mmci: avoid fake busy polling in mmci_irq
  mmc: mmci: fix clear of busy detect status
  mmc: mmci: add hardware busy timeout feature
  mmc: mmci: add busy detect for stm32 sdmmc variant

 drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
 drivers/mmc/host/mmci.h |  3 +++
 2 files changed, 51 insertions(+), 13 deletions(-)

-- 
2.7.4

[PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch series adds busy detect for stm32 sdmmc variant.
Some adaptations are required:
-Avoid to check and poll busy status when is not expected.
-Clear busy status bit if busy_detect_flag and busy_detect_mask are
 different.
-Add hardware busy timeout with MMCIDATATIMER register.

V2:
-mmci_cmd_irq cleanup in separate patch.
-simplify the busy_detect_flag exclude
-replace sdmmc specific comment in
"mmc: mmci: avoid fake busy polling in mmci_irq"
to focus on common behavior

Ludovic Barre (5):
  mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
  mmc: mmci: avoid fake busy polling in mmci_irq
  mmc: mmci: fix clear of busy detect status
  mmc: mmci: add hardware busy timeout feature
  mmc: mmci: add busy detect for stm32 sdmmc variant

 drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
 drivers/mmc/host/mmci.h |  3 +++
 2 files changed, 51 insertions(+), 13 deletions(-)

-- 
2.7.4


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[PATCH V2 1/5] mmc: mmci: cleanup mmci_cmd_irq for busy detect feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch cleans mmci_cmd_irq function for busy detect feature.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 9e9596a..049f8e3 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1205,12 +1205,13 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	     unsigned int status)
 {
 	void __iomem *base = host->base;
-	bool sbc;
+	bool sbc, busy_resp;
 
 	if (!cmd)
 		return;
 
 	sbc = (cmd == host->mrq->sbc);
+	busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
 
 	/*
 	 * We need to be one of these interrupts to be considered worth
@@ -1224,8 +1225,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	/*
 	 * ST Micro variant: handle busy detection.
 	 */
-	if (host->variant->busy_detect) {
-		bool busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
+	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
 		if (host->busy_status &&
@@ -1238,7 +1238,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status && busy_resp &&
+		if (!host->busy_status &&
 		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
 		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
 
-- 
2.7.4

[PATCH V2 1/5] mmc: mmci: cleanup mmci_cmd_irq for busy detect feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch cleans mmci_cmd_irq function for busy detect feature.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 9e9596a..049f8e3 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1205,12 +1205,13 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	     unsigned int status)
 {
 	void __iomem *base = host->base;
-	bool sbc;
+	bool sbc, busy_resp;
 
 	if (!cmd)
 		return;
 
 	sbc = (cmd == host->mrq->sbc);
+	busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
 
 	/*
 	 * We need to be one of these interrupts to be considered worth
@@ -1224,8 +1225,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	/*
 	 * ST Micro variant: handle busy detection.
 	 */
-	if (host->variant->busy_detect) {
-		bool busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
+	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
 		if (host->busy_status &&
@@ -1238,7 +1238,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status && busy_resp &&
+		if (!host->busy_status &&
 		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
 		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
 
-- 
2.7.4

[PATCH V2 1/5] mmc: mmci: cleanup mmci_cmd_irq for busy detect feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch cleans mmci_cmd_irq function for busy detect feature.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 9e9596a..049f8e3 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1205,12 +1205,13 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	     unsigned int status)
 {
 	void __iomem *base = host->base;
-	bool sbc;
+	bool sbc, busy_resp;
 
 	if (!cmd)
 		return;
 
 	sbc = (cmd == host->mrq->sbc);
+	busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
 
 	/*
 	 * We need to be one of these interrupts to be considered worth
@@ -1224,8 +1225,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	/*
 	 * ST Micro variant: handle busy detection.
 	 */
-	if (host->variant->busy_detect) {
-		bool busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
+	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
 		if (host->busy_status &&
@@ -1238,7 +1238,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status && busy_resp &&
+		if (!host->busy_status &&
 		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
 		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
 
-- 
2.7.4


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[PATCH V2 2/5] mmc: mmci: avoid fake busy polling in mmci_irq

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

mmci_irq function loops until the status is totally cleared.
However the busy_detect_flag could occurred even if no busy
response is expected and that busy d0 line is low (like in
cmd11: voltage switch).
Like busy_detect_flag is handled into mmci_cmd_irq this flag
can be always excluded.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 049f8e3..a040f54 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1535,9 +1535,10 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		}
 
 		/*
-		 * Don't poll for busy completion in irq context.
+		 * Busy_detect_flag has been handled by mmci_cmd_irq,
+		 * it can be excluded to avoid to poll on it
 		 */
-		if (host->variant->busy_detect && host->busy_status)
+		if (host->variant->busy_detect_flag)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
-- 
2.7.4

[PATCH V2 2/5] mmc: mmci: avoid fake busy polling in mmci_irq

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

mmci_irq function loops until the status is totally cleared.
However the busy_detect_flag could occurred even if no busy
response is expected and that busy d0 line is low (like in
cmd11: voltage switch).
Like busy_detect_flag is handled into mmci_cmd_irq this flag
can be always excluded.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 049f8e3..a040f54 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1535,9 +1535,10 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		}
 
 		/*
-		 * Don't poll for busy completion in irq context.
+		 * Busy_detect_flag has been handled by mmci_cmd_irq,
+		 * it can be excluded to avoid to poll on it
 		 */
-		if (host->variant->busy_detect && host->busy_status)
+		if (host->variant->busy_detect_flag)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
-- 
2.7.4

[PATCH V2 2/5] mmc: mmci: avoid fake busy polling in mmci_irq

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

mmci_irq function loops until the status is totally cleared.
However the busy_detect_flag could occurred even if no busy
response is expected and that busy d0 line is low (like in
cmd11: voltage switch).
Like busy_detect_flag is handled into mmci_cmd_irq this flag
can be always excluded.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 049f8e3..a040f54 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1535,9 +1535,10 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		}
 
 		/*
-		 * Don't poll for busy completion in irq context.
+		 * Busy_detect_flag has been handled by mmci_cmd_irq,
+		 * it can be excluded to avoid to poll on it
 		 */
-		if (host->variant->busy_detect && host->busy_status)
+		if (host->variant->busy_detect_flag)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
-- 
2.7.4


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[PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

The "busy_detect_flag" is used to read/clear busy value of
mmci status. The "busy_detect_mask" is used to manage busy irq of
mmci mask.
For sdmmc variant, the 2 properties have not the same offset.
To clear the busyd0 status bit, we must add busy detect flag,
the mmci mask is not enough.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a040f54..3cd52e8 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		 * to make sure that both start and end interrupts are always
 		 * cleared one after the other.
 		 */
-		status &= readl(host->base + MMCIMASK0);
+		status &= readl(host->base + MMCIMASK0) |
+			host->variant->busy_detect_flag;
 		if (host->variant->busy_detect)
 			writel(status & ~host->variant->busy_detect_mask,
 			       host->base + MMCICLEAR);
-- 
2.7.4

[PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

The "busy_detect_flag" is used to read/clear busy value of
mmci status. The "busy_detect_mask" is used to manage busy irq of
mmci mask.
For sdmmc variant, the 2 properties have not the same offset.
To clear the busyd0 status bit, we must add busy detect flag,
the mmci mask is not enough.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a040f54..3cd52e8 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		 * to make sure that both start and end interrupts are always
 		 * cleared one after the other.
 		 */
-		status &= readl(host->base + MMCIMASK0);
+		status &= readl(host->base + MMCIMASK0) |
+			host->variant->busy_detect_flag;
 		if (host->variant->busy_detect)
 			writel(status & ~host->variant->busy_detect_mask,
 			       host->base + MMCICLEAR);
-- 
2.7.4

[PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

The "busy_detect_flag" is used to read/clear busy value of
mmci status. The "busy_detect_mask" is used to manage busy irq of
mmci mask.
For sdmmc variant, the 2 properties have not the same offset.
To clear the busyd0 status bit, we must add busy detect flag,
the mmci mask is not enough.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a040f54..3cd52e8 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		 * to make sure that both start and end interrupts are always
 		 * cleared one after the other.
 		 */
-		status &= readl(host->base + MMCIMASK0);
+		status &= readl(host->base + MMCIMASK0) |
+			host->variant->busy_detect_flag;
 		if (host->variant->busy_detect)
 			writel(status & ~host->variant->busy_detect_mask,
 			       host->base + MMCICLEAR);
-- 
2.7.4


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[PATCH V2 4/5] mmc: mmci: add hardware busy timeout feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

In some variants, the data timer is enabled when the DPSM is in
busy state (while data transfert or MMC_RSP_BUSY), and could
generate a data timeout error if the counter reach 0.

-Define max_busy_timeout (in ms) according to clock.
-Set data timer register if the command has rsp_busy flag.
 If busy_timeout is not defined by framework, the busy
 length after Data Burst is defined as 1 second
 (refer: 4.6.2.2 Write of sd specification part1 v6-0).
-Add MCI_DATATIMEOUT error management in mmci_cmd_irq.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 43 ++++++++++++++++++++++++++++++++++++-------
 drivers/mmc/host/mmci.h |  2 ++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 3cd52e8..8dcb980 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1078,6 +1078,7 @@ static void
 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 {
 	void __iomem *base = host->base;
+	unsigned long long clks = 0;
 
 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
 	    cmd->opcode, cmd->arg, cmd->flags);
@@ -1100,6 +1101,19 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 		else
 			c |= host->variant->cmdreg_srsp;
 	}
+
+	if (host->variant->busy_timeout && !cmd->data) {
+		if (cmd->flags & MMC_RSP_BUSY) {
+			if (!cmd->busy_timeout)
+				cmd->busy_timeout = 1000;
+
+			clks = (unsigned long long)cmd->busy_timeout;
+			clks *=	host->cclk;
+			do_div(clks, MSEC_PER_SEC);
+		}
+		writel_relaxed(clks, host->base + MMCIDATATIMER);
+	}
+
 	if (/*interrupt*/0)
 		c |= MCI_CPSM_INTERRUPT;
 
@@ -1206,6 +1220,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 {
 	void __iomem *base = host->base;
 	bool sbc, busy_resp;
+	u32 err_msk;
 
 	if (!cmd)
 		return;
@@ -1218,8 +1233,12 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	 * handling. Note that we tag on any latent IRQs postponed
 	 * due to waiting for busy status.
 	 */
-	if (!((status|host->busy_status) &
-	      (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND)))
+	err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT;
+	if (host->variant->busy_timeout && busy_resp)
+		err_msk |= MCI_DATATIMEOUT;
+
+	if (!((status | host->busy_status) &
+	      (err_msk | MCI_CMDSENT | MCI_CMDRESPEND)))
 		return;
 
 	/*
@@ -1228,7 +1247,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
-		if (host->busy_status &&
+		if (host->busy_status && !(status & (err_msk)) &&
 		    (status & host->variant->busy_detect_flag))
 			return;
 
@@ -1238,9 +1257,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status &&
-		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
-		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
+		if (!host->busy_status && !(status & (err_msk)) &&
+		    (readl(base + MMCISTATUS) &
+		     host->variant->busy_detect_flag)) {
 
 			/* Clear the busy start IRQ */
 			writel(host->variant->busy_detect_mask,
@@ -1282,6 +1301,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		cmd->error = -ETIMEDOUT;
 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
 		cmd->error = -EILSEQ;
+	} else if (host->variant->busy_timeout && busy_resp &&
+		   status & MCI_DATATIMEOUT) {
+		cmd->error = -ETIMEDOUT;
 	} else {
 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
@@ -1543,6 +1565,7 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
+
 	} while (status);
 
 	spin_unlock(&host->lock);
@@ -1947,6 +1970,8 @@ static int mmci_probe(struct amba_device *dev,
 	 * Enable busy detection.
 	 */
 	if (variant->busy_detect) {
+		u32 max_busy_timeout = 0;
+
 		mmci_ops.card_busy = mmci_card_busy;
 		/*
 		 * Not all variants have a flag to enable busy detection
@@ -1956,7 +1981,11 @@ static int mmci_probe(struct amba_device *dev,
 			mmci_write_datactrlreg(host,
 					       host->variant->busy_dpsm_flag);
 		mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
-		mmc->max_busy_timeout = 0;
+
+		if (variant->busy_timeout)
+			max_busy_timeout = ~0UL / (mmc->f_max / MSEC_PER_SEC);
+
+		mmc->max_busy_timeout = max_busy_timeout;
 	}
 
 	/* Prepare a CMD12 - needed to clear the DPSM on some variants. */
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 4f071bd..b43a958 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -290,6 +290,7 @@ struct mmci_host;
  * @signal_direction: input/out direction of bus signals can be indicated
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
  * @busy_detect: true if the variant supports busy detection on DAT0.
+ * @busy_timeout: true if the variant supports hardware busy timeout on R1B.
  * @busy_dpsm_flag: bitmask enabling busy detection in the DPSM
  * @busy_detect_flag: bitmask identifying the bit in the MMCISTATUS register
  *		      indicating that the card is busy
@@ -336,6 +337,7 @@ struct variant_data {
 	u8			signal_direction:1;
 	u8			pwrreg_clkgate:1;
 	u8			busy_detect:1;
+	u8			busy_timeout:1;
 	u32			busy_dpsm_flag;
 	u32			busy_detect_flag;
 	u32			busy_detect_mask;
-- 
2.7.4

[PATCH V2 4/5] mmc: mmci: add hardware busy timeout feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

In some variants, the data timer is enabled when the DPSM is in
busy state (while data transfert or MMC_RSP_BUSY), and could
generate a data timeout error if the counter reach 0.

-Define max_busy_timeout (in ms) according to clock.
-Set data timer register if the command has rsp_busy flag.
 If busy_timeout is not defined by framework, the busy
 length after Data Burst is defined as 1 second
 (refer: 4.6.2.2 Write of sd specification part1 v6-0).
-Add MCI_DATATIMEOUT error management in mmci_cmd_irq.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 43 ++++++++++++++++++++++++++++++++++++-------
 drivers/mmc/host/mmci.h |  2 ++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 3cd52e8..8dcb980 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1078,6 +1078,7 @@ static void
 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 {
 	void __iomem *base = host->base;
+	unsigned long long clks = 0;
 
 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
 	    cmd->opcode, cmd->arg, cmd->flags);
@@ -1100,6 +1101,19 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 		else
 			c |= host->variant->cmdreg_srsp;
 	}
+
+	if (host->variant->busy_timeout && !cmd->data) {
+		if (cmd->flags & MMC_RSP_BUSY) {
+			if (!cmd->busy_timeout)
+				cmd->busy_timeout = 1000;
+
+			clks = (unsigned long long)cmd->busy_timeout;
+			clks *=	host->cclk;
+			do_div(clks, MSEC_PER_SEC);
+		}
+		writel_relaxed(clks, host->base + MMCIDATATIMER);
+	}
+
 	if (/*interrupt*/0)
 		c |= MCI_CPSM_INTERRUPT;
 
@@ -1206,6 +1220,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 {
 	void __iomem *base = host->base;
 	bool sbc, busy_resp;
+	u32 err_msk;
 
 	if (!cmd)
 		return;
@@ -1218,8 +1233,12 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	 * handling. Note that we tag on any latent IRQs postponed
 	 * due to waiting for busy status.
 	 */
-	if (!((status|host->busy_status) &
-	      (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND)))
+	err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT;
+	if (host->variant->busy_timeout && busy_resp)
+		err_msk |= MCI_DATATIMEOUT;
+
+	if (!((status | host->busy_status) &
+	      (err_msk | MCI_CMDSENT | MCI_CMDRESPEND)))
 		return;
 
 	/*
@@ -1228,7 +1247,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
-		if (host->busy_status &&
+		if (host->busy_status && !(status & (err_msk)) &&
 		    (status & host->variant->busy_detect_flag))
 			return;
 
@@ -1238,9 +1257,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status &&
-		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
-		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
+		if (!host->busy_status && !(status & (err_msk)) &&
+		    (readl(base + MMCISTATUS) &
+		     host->variant->busy_detect_flag)) {
 
 			/* Clear the busy start IRQ */
 			writel(host->variant->busy_detect_mask,
@@ -1282,6 +1301,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		cmd->error = -ETIMEDOUT;
 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
 		cmd->error = -EILSEQ;
+	} else if (host->variant->busy_timeout && busy_resp &&
+		   status & MCI_DATATIMEOUT) {
+		cmd->error = -ETIMEDOUT;
 	} else {
 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
@@ -1543,6 +1565,7 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
+
 	} while (status);
 
 	spin_unlock(&host->lock);
@@ -1947,6 +1970,8 @@ static int mmci_probe(struct amba_device *dev,
 	 * Enable busy detection.
 	 */
 	if (variant->busy_detect) {
+		u32 max_busy_timeout = 0;
+
 		mmci_ops.card_busy = mmci_card_busy;
 		/*
 		 * Not all variants have a flag to enable busy detection
@@ -1956,7 +1981,11 @@ static int mmci_probe(struct amba_device *dev,
 			mmci_write_datactrlreg(host,
 					       host->variant->busy_dpsm_flag);
 		mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
-		mmc->max_busy_timeout = 0;
+
+		if (variant->busy_timeout)
+			max_busy_timeout = ~0UL / (mmc->f_max / MSEC_PER_SEC);
+
+		mmc->max_busy_timeout = max_busy_timeout;
 	}
 
 	/* Prepare a CMD12 - needed to clear the DPSM on some variants. */
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 4f071bd..b43a958 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -290,6 +290,7 @@ struct mmci_host;
  * @signal_direction: input/out direction of bus signals can be indicated
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
  * @busy_detect: true if the variant supports busy detection on DAT0.
+ * @busy_timeout: true if the variant supports hardware busy timeout on R1B.
  * @busy_dpsm_flag: bitmask enabling busy detection in the DPSM
  * @busy_detect_flag: bitmask identifying the bit in the MMCISTATUS register
  *		      indicating that the card is busy
@@ -336,6 +337,7 @@ struct variant_data {
 	u8			signal_direction:1;
 	u8			pwrreg_clkgate:1;
 	u8			busy_detect:1;
+	u8			busy_timeout:1;
 	u32			busy_dpsm_flag;
 	u32			busy_detect_flag;
 	u32			busy_detect_mask;
-- 
2.7.4

[PATCH V2 4/5] mmc: mmci: add hardware busy timeout feature

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

In some variants, the data timer is enabled when the DPSM is in
busy state (while data transfert or MMC_RSP_BUSY), and could
generate a data timeout error if the counter reach 0.

-Define max_busy_timeout (in ms) according to clock.
-Set data timer register if the command has rsp_busy flag.
 If busy_timeout is not defined by framework, the busy
 length after Data Burst is defined as 1 second
 (refer: 4.6.2.2 Write of sd specification part1 v6-0).
-Add MCI_DATATIMEOUT error management in mmci_cmd_irq.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 43 ++++++++++++++++++++++++++++++++++++-------
 drivers/mmc/host/mmci.h |  2 ++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 3cd52e8..8dcb980 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1078,6 +1078,7 @@ static void
 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 {
 	void __iomem *base = host->base;
+	unsigned long long clks = 0;
 
 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
 	    cmd->opcode, cmd->arg, cmd->flags);
@@ -1100,6 +1101,19 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 		else
 			c |= host->variant->cmdreg_srsp;
 	}
+
+	if (host->variant->busy_timeout && !cmd->data) {
+		if (cmd->flags & MMC_RSP_BUSY) {
+			if (!cmd->busy_timeout)
+				cmd->busy_timeout = 1000;
+
+			clks = (unsigned long long)cmd->busy_timeout;
+			clks *=	host->cclk;
+			do_div(clks, MSEC_PER_SEC);
+		}
+		writel_relaxed(clks, host->base + MMCIDATATIMER);
+	}
+
 	if (/*interrupt*/0)
 		c |= MCI_CPSM_INTERRUPT;
 
@@ -1206,6 +1220,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 {
 	void __iomem *base = host->base;
 	bool sbc, busy_resp;
+	u32 err_msk;
 
 	if (!cmd)
 		return;
@@ -1218,8 +1233,12 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	 * handling. Note that we tag on any latent IRQs postponed
 	 * due to waiting for busy status.
 	 */
-	if (!((status|host->busy_status) &
-	      (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND)))
+	err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT;
+	if (host->variant->busy_timeout && busy_resp)
+		err_msk |= MCI_DATATIMEOUT;
+
+	if (!((status | host->busy_status) &
+	      (err_msk | MCI_CMDSENT | MCI_CMDRESPEND)))
 		return;
 
 	/*
@@ -1228,7 +1247,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (busy_resp && host->variant->busy_detect) {
 
 		/* We are busy with a command, return */
-		if (host->busy_status &&
+		if (host->busy_status && !(status & (err_msk)) &&
 		    (status & host->variant->busy_detect_flag))
 			return;
 
@@ -1238,9 +1257,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		 * that the special busy status bit is still set before
 		 * proceeding.
 		 */
-		if (!host->busy_status &&
-		    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
-		    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
+		if (!host->busy_status && !(status & (err_msk)) &&
+		    (readl(base + MMCISTATUS) &
+		     host->variant->busy_detect_flag)) {
 
 			/* Clear the busy start IRQ */
 			writel(host->variant->busy_detect_mask,
@@ -1282,6 +1301,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 		cmd->error = -ETIMEDOUT;
 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
 		cmd->error = -EILSEQ;
+	} else if (host->variant->busy_timeout && busy_resp &&
+		   status & MCI_DATATIMEOUT) {
+		cmd->error = -ETIMEDOUT;
 	} else {
 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
@@ -1543,6 +1565,7 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
+
 	} while (status);
 
 	spin_unlock(&host->lock);
@@ -1947,6 +1970,8 @@ static int mmci_probe(struct amba_device *dev,
 	 * Enable busy detection.
 	 */
 	if (variant->busy_detect) {
+		u32 max_busy_timeout = 0;
+
 		mmci_ops.card_busy = mmci_card_busy;
 		/*
 		 * Not all variants have a flag to enable busy detection
@@ -1956,7 +1981,11 @@ static int mmci_probe(struct amba_device *dev,
 			mmci_write_datactrlreg(host,
 					       host->variant->busy_dpsm_flag);
 		mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
-		mmc->max_busy_timeout = 0;
+
+		if (variant->busy_timeout)
+			max_busy_timeout = ~0UL / (mmc->f_max / MSEC_PER_SEC);
+
+		mmc->max_busy_timeout = max_busy_timeout;
 	}
 
 	/* Prepare a CMD12 - needed to clear the DPSM on some variants. */
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 4f071bd..b43a958 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -290,6 +290,7 @@ struct mmci_host;
  * @signal_direction: input/out direction of bus signals can be indicated
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
  * @busy_detect: true if the variant supports busy detection on DAT0.
+ * @busy_timeout: true if the variant supports hardware busy timeout on R1B.
  * @busy_dpsm_flag: bitmask enabling busy detection in the DPSM
  * @busy_detect_flag: bitmask identifying the bit in the MMCISTATUS register
  *		      indicating that the card is busy
@@ -336,6 +337,7 @@ struct variant_data {
 	u8			signal_direction:1;
 	u8			pwrreg_clkgate:1;
 	u8			busy_detect:1;
+	u8			busy_timeout:1;
 	u32			busy_dpsm_flag;
 	u32			busy_detect_flag;
 	u32			busy_detect_mask;
-- 
2.7.4


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[PATCH V2 5/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch enables busy detection for stm32 sdmmc which requires
to set data timer to define the busy timeout.
sdmmc has 2 flags:
-busyd0: inverted value of d0 line.
-busyd0end which indicates only end of busy following a cmd response.
Only one interrupt on busyd0end.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 4 ++++
 drivers/mmc/host/mmci.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8dcb980..02a3cdd 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -264,6 +264,10 @@ static struct variant_data variant_stm32_sdmmc = {
 	.datalength_bits	= 25,
 	.datactrl_blocksz	= 14,
 	.stm32_idmabsize_mask	= GENMASK(12, 5),
+	.busy_detect		= true,
+	.busy_timeout		= true,
+	.busy_detect_flag	= MCI_STM32_BUSYD0,
+	.busy_detect_mask	= MCI_STM32_BUSYD0ENDMASK,
 	.init			= sdmmc_variant_init,
 };
 
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index b43a958..ac19de8 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -167,6 +167,7 @@
 #define MCI_ST_CARDBUSY		(1 << 24)
 /* Extended status bits for the STM32 variants */
 #define MCI_STM32_BUSYD0	BIT(20)
+#define MCI_STM32_BUSYD0END	BIT(21)
 
 #define MMCICLEAR		0x038
 #define MCI_CMDCRCFAILCLR	(1 << 0)
-- 
2.7.4

[PATCH V2 5/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch enables busy detection for stm32 sdmmc which requires
to set data timer to define the busy timeout.
sdmmc has 2 flags:
-busyd0: inverted value of d0 line.
-busyd0end which indicates only end of busy following a cmd response.
Only one interrupt on busyd0end.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 4 ++++
 drivers/mmc/host/mmci.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8dcb980..02a3cdd 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -264,6 +264,10 @@ static struct variant_data variant_stm32_sdmmc = {
 	.datalength_bits	= 25,
 	.datactrl_blocksz	= 14,
 	.stm32_idmabsize_mask	= GENMASK(12, 5),
+	.busy_detect		= true,
+	.busy_timeout		= true,
+	.busy_detect_flag	= MCI_STM32_BUSYD0,
+	.busy_detect_mask	= MCI_STM32_BUSYD0ENDMASK,
 	.init			= sdmmc_variant_init,
 };
 
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index b43a958..ac19de8 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -167,6 +167,7 @@
 #define MCI_ST_CARDBUSY		(1 << 24)
 /* Extended status bits for the STM32 variants */
 #define MCI_STM32_BUSYD0	BIT(20)
+#define MCI_STM32_BUSYD0END	BIT(21)
 
 #define MMCICLEAR		0x038
 #define MCI_CMDCRCFAILCLR	(1 << 0)
-- 
2.7.4

[PATCH V2 5/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch enables busy detection for stm32 sdmmc which requires
to set data timer to define the busy timeout.
sdmmc has 2 flags:
-busyd0: inverted value of d0 line.
-busyd0end which indicates only end of busy following a cmd response.
Only one interrupt on busyd0end.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 4 ++++
 drivers/mmc/host/mmci.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8dcb980..02a3cdd 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -264,6 +264,10 @@ static struct variant_data variant_stm32_sdmmc = {
 	.datalength_bits	= 25,
 	.datactrl_blocksz	= 14,
 	.stm32_idmabsize_mask	= GENMASK(12, 5),
+	.busy_detect		= true,
+	.busy_timeout		= true,
+	.busy_detect_flag	= MCI_STM32_BUSYD0,
+	.busy_detect_mask	= MCI_STM32_BUSYD0ENDMASK,
 	.init			= sdmmc_variant_init,
 };
 
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index b43a958..ac19de8 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -167,6 +167,7 @@
 #define MCI_ST_CARDBUSY		(1 << 24)
 /* Extended status bits for the STM32 variants */
 #define MCI_STM32_BUSYD0	BIT(20)
+#define MCI_STM32_BUSYD0END	BIT(21)
 
 #define MMCICLEAR		0x038
 #define MCI_CMDCRCFAILCLR	(1 << 0)
-- 
2.7.4


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Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> This patch series adds busy detect for stm32 sdmmc variant.
> Some adaptations are required:
> -Avoid to check and poll busy status when is not expected.
> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>  different.
> -Add hardware busy timeout with MMCIDATATIMER register.
>
> V2:
> -mmci_cmd_irq cleanup in separate patch.
> -simplify the busy_detect_flag exclude
> -replace sdmmc specific comment in
> "mmc: mmci: avoid fake busy polling in mmci_irq"
> to focus on common behavior
>
> Ludovic Barre (5):
>   mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>   mmc: mmci: avoid fake busy polling in mmci_irq
>   mmc: mmci: fix clear of busy detect status
>   mmc: mmci: add hardware busy timeout feature
>   mmc: mmci: add busy detect for stm32 sdmmc variant
>
>  drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>  drivers/mmc/host/mmci.h |  3 +++
>  2 files changed, 51 insertions(+), 13 deletions(-)
>
> --
> 2.7.4
>

Ludovic, just wanted to let you know that I am reviewing and testing
this series.

However, while running some tests on Ux500 for validating the busy
detection code, even without your series applied, I encounter some odd
behaviors. I am looking into the problem to understand better and will
let you know as soon as I have some more data to share.

Kind regards
Uffe

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> This patch series adds busy detect for stm32 sdmmc variant.
> Some adaptations are required:
> -Avoid to check and poll busy status when is not expected.
> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>  different.
> -Add hardware busy timeout with MMCIDATATIMER register.
>
> V2:
> -mmci_cmd_irq cleanup in separate patch.
> -simplify the busy_detect_flag exclude
> -replace sdmmc specific comment in
> "mmc: mmci: avoid fake busy polling in mmci_irq"
> to focus on common behavior
>
> Ludovic Barre (5):
>   mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>   mmc: mmci: avoid fake busy polling in mmci_irq
>   mmc: mmci: fix clear of busy detect status
>   mmc: mmci: add hardware busy timeout feature
>   mmc: mmci: add busy detect for stm32 sdmmc variant
>
>  drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>  drivers/mmc/host/mmci.h |  3 +++
>  2 files changed, 51 insertions(+), 13 deletions(-)
>
> --
> 2.7.4
>

Ludovic, just wanted to let you know that I am reviewing and testing
this series.

However, while running some tests on Ux500 for validating the busy
detection code, even without your series applied, I encounter some odd
behaviors. I am looking into the problem to understand better and will
let you know as soon as I have some more data to share.

Kind regards
Uffe

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 4/30/19 1:13 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> This patch series adds busy detect for stm32 sdmmc variant.
>> Some adaptations are required:
>> -Avoid to check and poll busy status when is not expected.
>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>   different.
>> -Add hardware busy timeout with MMCIDATATIMER register.
>>
>> V2:
>> -mmci_cmd_irq cleanup in separate patch.
>> -simplify the busy_detect_flag exclude
>> -replace sdmmc specific comment in
>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>> to focus on common behavior
>>
>> Ludovic Barre (5):
>>    mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>    mmc: mmci: avoid fake busy polling in mmci_irq
>>    mmc: mmci: fix clear of busy detect status
>>    mmc: mmci: add hardware busy timeout feature
>>    mmc: mmci: add busy detect for stm32 sdmmc variant
>>
>>   drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>   drivers/mmc/host/mmci.h |  3 +++
>>   2 files changed, 51 insertions(+), 13 deletions(-)
>>
>> --
>> 2.7.4
>>
> 
> Ludovic, just wanted to let you know that I am reviewing and testing
> this series.
> 
> However, while running some tests on Ux500 for validating the busy
> detection code, even without your series applied, I encounter some odd
> behaviors. I am looking into the problem to understand better and will
> let you know as soon as I have some more data to share.

Oops, don't hesitate to share your status, if I could help.

> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 4/30/19 1:13 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> This patch series adds busy detect for stm32 sdmmc variant.
>> Some adaptations are required:
>> -Avoid to check and poll busy status when is not expected.
>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>   different.
>> -Add hardware busy timeout with MMCIDATATIMER register.
>>
>> V2:
>> -mmci_cmd_irq cleanup in separate patch.
>> -simplify the busy_detect_flag exclude
>> -replace sdmmc specific comment in
>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>> to focus on common behavior
>>
>> Ludovic Barre (5):
>>    mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>    mmc: mmci: avoid fake busy polling in mmci_irq
>>    mmc: mmci: fix clear of busy detect status
>>    mmc: mmci: add hardware busy timeout feature
>>    mmc: mmci: add busy detect for stm32 sdmmc variant
>>
>>   drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>   drivers/mmc/host/mmci.h |  3 +++
>>   2 files changed, 51 insertions(+), 13 deletions(-)
>>
>> --
>> 2.7.4
>>
> 
> Ludovic, just wanted to let you know that I am reviewing and testing
> this series.
> 
> However, while running some tests on Ux500 for validating the busy
> detection code, even without your series applied, I encounter some odd
> behaviors. I am looking into the problem to understand better and will
> let you know as soon as I have some more data to share.

Oops, don't hesitate to share your status, if I could help.

> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 4/30/19 1:13 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> This patch series adds busy detect for stm32 sdmmc variant.
>> Some adaptations are required:
>> -Avoid to check and poll busy status when is not expected.
>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>   different.
>> -Add hardware busy timeout with MMCIDATATIMER register.
>>
>> V2:
>> -mmci_cmd_irq cleanup in separate patch.
>> -simplify the busy_detect_flag exclude
>> -replace sdmmc specific comment in
>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>> to focus on common behavior
>>
>> Ludovic Barre (5):
>>    mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>    mmc: mmci: avoid fake busy polling in mmci_irq
>>    mmc: mmci: fix clear of busy detect status
>>    mmc: mmci: add hardware busy timeout feature
>>    mmc: mmci: add busy detect for stm32 sdmmc variant
>>
>>   drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>   drivers/mmc/host/mmci.h |  3 +++
>>   2 files changed, 51 insertions(+), 13 deletions(-)
>>
>> --
>> 2.7.4
>>
> 
> Ludovic, just wanted to let you know that I am reviewing and testing
> this series.
> 
> However, while running some tests on Ux500 for validating the busy
> detection code, even without your series applied, I encounter some odd
> behaviors. I am looking into the problem to understand better and will
> let you know as soon as I have some more data to share.

Oops, don't hesitate to share your status, if I could help.

> 
> Kind regards
> Uffe
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
>
>
> On 4/30/19 1:13 PM, Ulf Hansson wrote:
> > On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>
> >> From: Ludovic Barre <ludovic.barre@st.com>
> >>
> >> This patch series adds busy detect for stm32 sdmmc variant.
> >> Some adaptations are required:
> >> -Avoid to check and poll busy status when is not expected.
> >> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
> >>   different.
> >> -Add hardware busy timeout with MMCIDATATIMER register.
> >>
> >> V2:
> >> -mmci_cmd_irq cleanup in separate patch.
> >> -simplify the busy_detect_flag exclude
> >> -replace sdmmc specific comment in
> >> "mmc: mmci: avoid fake busy polling in mmci_irq"
> >> to focus on common behavior
> >>
> >> Ludovic Barre (5):
> >>    mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
> >>    mmc: mmci: avoid fake busy polling in mmci_irq
> >>    mmc: mmci: fix clear of busy detect status
> >>    mmc: mmci: add hardware busy timeout feature
> >>    mmc: mmci: add busy detect for stm32 sdmmc variant
> >>
> >>   drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
> >>   drivers/mmc/host/mmci.h |  3 +++
> >>   2 files changed, 51 insertions(+), 13 deletions(-)
> >>
> >> --
> >> 2.7.4
> >>
> >
> > Ludovic, just wanted to let you know that I am reviewing and testing
> > this series.
> >
> > However, while running some tests on Ux500 for validating the busy
> > detection code, even without your series applied, I encounter some odd
> > behaviors. I am looking into the problem to understand better and will
> > let you know as soon as I have some more data to share.
>
> Oops, don't hesitate to share your status, if I could help.

Thanks! Good and bad news here, then.

I now understand what is going on - and there is certainly room for
improvements here, but more importantly the actual mmci busy detection
works as expected.

When it comes to improvements, the main issue I have found is how we
treat DATA WRITES. In many cases we simply don't use the HW busy
detection at all, but instead rely on the mmc core to send CMD13 in a
loop to poll. Well, then if the polling would have consisted of a
couple of CMD13s that wouldn't be an issue, but my observations is
rather that the numbers of CMD13 sent to poll is in the range or
hundreds/thousands - per each WRITE request!

I am going to send a patch (or two) that improves the behavior. It
might even involve changing parts in core layer, not sure how the end
result will look like yet.

In any case, I have applied patch 1 and patch2 for next, as the tests
turned out well at my side. I also took the liberty of updating some
of the comments/changelogs, please have look and tell if there is
something you want to change.

I will continue with the rest of series next week.

Kind regards
Uffe

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
>
>
> On 4/30/19 1:13 PM, Ulf Hansson wrote:
> > On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>
> >> From: Ludovic Barre <ludovic.barre@st.com>
> >>
> >> This patch series adds busy detect for stm32 sdmmc variant.
> >> Some adaptations are required:
> >> -Avoid to check and poll busy status when is not expected.
> >> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
> >>   different.
> >> -Add hardware busy timeout with MMCIDATATIMER register.
> >>
> >> V2:
> >> -mmci_cmd_irq cleanup in separate patch.
> >> -simplify the busy_detect_flag exclude
> >> -replace sdmmc specific comment in
> >> "mmc: mmci: avoid fake busy polling in mmci_irq"
> >> to focus on common behavior
> >>
> >> Ludovic Barre (5):
> >>    mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
> >>    mmc: mmci: avoid fake busy polling in mmci_irq
> >>    mmc: mmci: fix clear of busy detect status
> >>    mmc: mmci: add hardware busy timeout feature
> >>    mmc: mmci: add busy detect for stm32 sdmmc variant
> >>
> >>   drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
> >>   drivers/mmc/host/mmci.h |  3 +++
> >>   2 files changed, 51 insertions(+), 13 deletions(-)
> >>
> >> --
> >> 2.7.4
> >>
> >
> > Ludovic, just wanted to let you know that I am reviewing and testing
> > this series.
> >
> > However, while running some tests on Ux500 for validating the busy
> > detection code, even without your series applied, I encounter some odd
> > behaviors. I am looking into the problem to understand better and will
> > let you know as soon as I have some more data to share.
>
> Oops, don't hesitate to share your status, if I could help.

Thanks! Good and bad news here, then.

I now understand what is going on - and there is certainly room for
improvements here, but more importantly the actual mmci busy detection
works as expected.

When it comes to improvements, the main issue I have found is how we
treat DATA WRITES. In many cases we simply don't use the HW busy
detection at all, but instead rely on the mmc core to send CMD13 in a
loop to poll. Well, then if the polling would have consisted of a
couple of CMD13s that wouldn't be an issue, but my observations is
rather that the numbers of CMD13 sent to poll is in the range or
hundreds/thousands - per each WRITE request!

I am going to send a patch (or two) that improves the behavior. It
might even involve changing parts in core layer, not sure how the end
result will look like yet.

In any case, I have applied patch 1 and patch2 for next, as the tests
turned out well at my side. I also took the liberty of updating some
of the comments/changelogs, please have look and tell if there is
something you want to change.

I will continue with the rest of series next week.

Kind regards
Uffe

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.

yes, these will improve the drivers without hardware busy completion.
great

> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.

thanks, and good week-end.

> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.

yes, these will improve the drivers without hardware busy completion.
great

> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.

thanks, and good week-end.

> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.

yes, these will improve the drivers without hardware busy completion.
great

> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.

thanks, and good week-end.

> 
> Kind regards
> Uffe
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

Just a "gentleman ping" about the rest of series.
"mmc: mmci: add busy detect for stm32 sdmmc variant"

Regards
Ludo

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.
> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.
> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

Just a "gentleman ping" about the rest of series.
"mmc: mmci: add busy detect for stm32 sdmmc variant"

Regards
Ludo

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.
> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.
> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

hi Ulf

Just a "gentleman ping" about the rest of series.
"mmc: mmci: add busy detect for stm32 sdmmc variant"

Regards
Ludo

On 5/3/19 3:29 PM, Ulf Hansson wrote:
> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>>
>>
>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>> Some adaptations are required:
>>>> -Avoid to check and poll busy status when is not expected.
>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>    different.
>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>
>>>> V2:
>>>> -mmci_cmd_irq cleanup in separate patch.
>>>> -simplify the busy_detect_flag exclude
>>>> -replace sdmmc specific comment in
>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>> to focus on common behavior
>>>>
>>>> Ludovic Barre (5):
>>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>     mmc: mmci: avoid fake busy polling in mmci_irq
>>>>     mmc: mmci: fix clear of busy detect status
>>>>     mmc: mmci: add hardware busy timeout feature
>>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>
>>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>    drivers/mmc/host/mmci.h |  3 +++
>>>>    2 files changed, 51 insertions(+), 13 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
>>>>
>>>
>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>> this series.
>>>
>>> However, while running some tests on Ux500 for validating the busy
>>> detection code, even without your series applied, I encounter some odd
>>> behaviors. I am looking into the problem to understand better and will
>>> let you know as soon as I have some more data to share.
>>
>> Oops, don't hesitate to share your status, if I could help.
> 
> Thanks! Good and bad news here, then.
> 
> I now understand what is going on - and there is certainly room for
> improvements here, but more importantly the actual mmci busy detection
> works as expected.
> 
> When it comes to improvements, the main issue I have found is how we
> treat DATA WRITES. In many cases we simply don't use the HW busy
> detection at all, but instead rely on the mmc core to send CMD13 in a
> loop to poll. Well, then if the polling would have consisted of a
> couple of CMD13s that wouldn't be an issue, but my observations is
> rather that the numbers of CMD13 sent to poll is in the range or
> hundreds/thousands - per each WRITE request!
> 
> I am going to send a patch (or two) that improves the behavior. It
> might even involve changing parts in core layer, not sure how the end
> result will look like yet.
> 
> In any case, I have applied patch 1 and patch2 for next, as the tests
> turned out well at my side. I also took the liberty of updating some
> of the comments/changelogs, please have look and tell if there is
> something you want to change.
> 
> I will continue with the rest of series next week.
> 
> Kind regards
> Uffe
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Tue, 21 May 2019 at 09:38, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
> hi Ulf
>
> Just a "gentleman ping" about the rest of series.
> "mmc: mmci: add busy detect for stm32 sdmmc variant"

Thanks!

It's been a busy period and I am currently traveling. My plan is to
look at in detail beginning of next week when get back home. I hope
that's okay.

Kind regards
Uffe

>
> Regards
> Ludo
>
> On 5/3/19 3:29 PM, Ulf Hansson wrote:
> > On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
> >>
> >>
> >>
> >> On 4/30/19 1:13 PM, Ulf Hansson wrote:
> >>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>>>
> >>>> From: Ludovic Barre <ludovic.barre@st.com>
> >>>>
> >>>> This patch series adds busy detect for stm32 sdmmc variant.
> >>>> Some adaptations are required:
> >>>> -Avoid to check and poll busy status when is not expected.
> >>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
> >>>>    different.
> >>>> -Add hardware busy timeout with MMCIDATATIMER register.
> >>>>
> >>>> V2:
> >>>> -mmci_cmd_irq cleanup in separate patch.
> >>>> -simplify the busy_detect_flag exclude
> >>>> -replace sdmmc specific comment in
> >>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
> >>>> to focus on common behavior
> >>>>
> >>>> Ludovic Barre (5):
> >>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
> >>>>     mmc: mmci: avoid fake busy polling in mmci_irq
> >>>>     mmc: mmci: fix clear of busy detect status
> >>>>     mmc: mmci: add hardware busy timeout feature
> >>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
> >>>>
> >>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
> >>>>    drivers/mmc/host/mmci.h |  3 +++
> >>>>    2 files changed, 51 insertions(+), 13 deletions(-)
> >>>>
> >>>> --
> >>>> 2.7.4
> >>>>
> >>>
> >>> Ludovic, just wanted to let you know that I am reviewing and testing
> >>> this series.
> >>>
> >>> However, while running some tests on Ux500 for validating the busy
> >>> detection code, even without your series applied, I encounter some odd
> >>> behaviors. I am looking into the problem to understand better and will
> >>> let you know as soon as I have some more data to share.
> >>
> >> Oops, don't hesitate to share your status, if I could help.
> >
> > Thanks! Good and bad news here, then.
> >
> > I now understand what is going on - and there is certainly room for
> > improvements here, but more importantly the actual mmci busy detection
> > works as expected.
> >
> > When it comes to improvements, the main issue I have found is how we
> > treat DATA WRITES. In many cases we simply don't use the HW busy
> > detection at all, but instead rely on the mmc core to send CMD13 in a
> > loop to poll. Well, then if the polling would have consisted of a
> > couple of CMD13s that wouldn't be an issue, but my observations is
> > rather that the numbers of CMD13 sent to poll is in the range or
> > hundreds/thousands - per each WRITE request!
> >
> > I am going to send a patch (or two) that improves the behavior. It
> > might even involve changing parts in core layer, not sure how the end
> > result will look like yet.
> >
> > In any case, I have applied patch 1 and patch2 for next, as the tests
> > turned out well at my side. I also took the liberty of updating some
> > of the comments/changelogs, please have look and tell if there is
> > something you want to change.
> >
> > I will continue with the rest of series next week.
> >
> > Kind regards
> > Uffe
> >

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ulf Hansson]

On Tue, 21 May 2019 at 09:38, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
> hi Ulf
>
> Just a "gentleman ping" about the rest of series.
> "mmc: mmci: add busy detect for stm32 sdmmc variant"

Thanks!

It's been a busy period and I am currently traveling. My plan is to
look at in detail beginning of next week when get back home. I hope
that's okay.

Kind regards
Uffe

>
> Regards
> Ludo
>
> On 5/3/19 3:29 PM, Ulf Hansson wrote:
> > On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
> >>
> >>
> >>
> >> On 4/30/19 1:13 PM, Ulf Hansson wrote:
> >>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>>>
> >>>> From: Ludovic Barre <ludovic.barre@st.com>
> >>>>
> >>>> This patch series adds busy detect for stm32 sdmmc variant.
> >>>> Some adaptations are required:
> >>>> -Avoid to check and poll busy status when is not expected.
> >>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
> >>>>    different.
> >>>> -Add hardware busy timeout with MMCIDATATIMER register.
> >>>>
> >>>> V2:
> >>>> -mmci_cmd_irq cleanup in separate patch.
> >>>> -simplify the busy_detect_flag exclude
> >>>> -replace sdmmc specific comment in
> >>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
> >>>> to focus on common behavior
> >>>>
> >>>> Ludovic Barre (5):
> >>>>     mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
> >>>>     mmc: mmci: avoid fake busy polling in mmci_irq
> >>>>     mmc: mmci: fix clear of busy detect status
> >>>>     mmc: mmci: add hardware busy timeout feature
> >>>>     mmc: mmci: add busy detect for stm32 sdmmc variant
> >>>>
> >>>>    drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
> >>>>    drivers/mmc/host/mmci.h |  3 +++
> >>>>    2 files changed, 51 insertions(+), 13 deletions(-)
> >>>>
> >>>> --
> >>>> 2.7.4
> >>>>
> >>>
> >>> Ludovic, just wanted to let you know that I am reviewing and testing
> >>> this series.
> >>>
> >>> However, while running some tests on Ux500 for validating the busy
> >>> detection code, even without your series applied, I encounter some odd
> >>> behaviors. I am looking into the problem to understand better and will
> >>> let you know as soon as I have some more data to share.
> >>
> >> Oops, don't hesitate to share your status, if I could help.
> >
> > Thanks! Good and bad news here, then.
> >
> > I now understand what is going on - and there is certainly room for
> > improvements here, but more importantly the actual mmci busy detection
> > works as expected.
> >
> > When it comes to improvements, the main issue I have found is how we
> > treat DATA WRITES. In many cases we simply don't use the HW busy
> > detection at all, but instead rely on the mmc core to send CMD13 in a
> > loop to poll. Well, then if the polling would have consisted of a
> > couple of CMD13s that wouldn't be an issue, but my observations is
> > rather that the numbers of CMD13 sent to poll is in the range or
> > hundreds/thousands - per each WRITE request!
> >
> > I am going to send a patch (or two) that improves the behavior. It
> > might even involve changing parts in core layer, not sure how the end
> > result will look like yet.
> >
> > In any case, I have applied patch 1 and patch2 for next, as the tests
> > turned out well at my side. I also took the liberty of updating some
> > of the comments/changelogs, please have look and tell if there is
> > something you want to change.
> >
> > I will continue with the rest of series next week.
> >
> > Kind regards
> > Uffe
> >

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 5/21/19 9:56 AM, Ulf Hansson wrote:
> On Tue, 21 May 2019 at 09:38, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>> hi Ulf
>>
>> Just a "gentleman ping" about the rest of series.
>> "mmc: mmci: add busy detect for stm32 sdmmc variant"
> 
> Thanks!
> 
> It's been a busy period and I am currently traveling. My plan is to
> look at in detail beginning of next week when get back home. I hope
> that's okay.

yes, I understand, it's just to not forget me :-)

> 
> Kind regards
> Uffe
> 
>>
>> Regards
>> Ludo
>>
>> On 5/3/19 3:29 PM, Ulf Hansson wrote:
>>> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>>>
>>>>
>>>>
>>>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>>>
>>>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>>>
>>>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>>>> Some adaptations are required:
>>>>>> -Avoid to check and poll busy status when is not expected.
>>>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>>>     different.
>>>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>>>
>>>>>> V2:
>>>>>> -mmci_cmd_irq cleanup in separate patch.
>>>>>> -simplify the busy_detect_flag exclude
>>>>>> -replace sdmmc specific comment in
>>>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>>>> to focus on common behavior
>>>>>>
>>>>>> Ludovic Barre (5):
>>>>>>      mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>>>      mmc: mmci: avoid fake busy polling in mmci_irq
>>>>>>      mmc: mmci: fix clear of busy detect status
>>>>>>      mmc: mmci: add hardware busy timeout feature
>>>>>>      mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>>>
>>>>>>     drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>>>     drivers/mmc/host/mmci.h |  3 +++
>>>>>>     2 files changed, 51 insertions(+), 13 deletions(-)
>>>>>>
>>>>>> --
>>>>>> 2.7.4
>>>>>>
>>>>>
>>>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>>>> this series.
>>>>>
>>>>> However, while running some tests on Ux500 for validating the busy
>>>>> detection code, even without your series applied, I encounter some odd
>>>>> behaviors. I am looking into the problem to understand better and will
>>>>> let you know as soon as I have some more data to share.
>>>>
>>>> Oops, don't hesitate to share your status, if I could help.
>>>
>>> Thanks! Good and bad news here, then.
>>>
>>> I now understand what is going on - and there is certainly room for
>>> improvements here, but more importantly the actual mmci busy detection
>>> works as expected.
>>>
>>> When it comes to improvements, the main issue I have found is how we
>>> treat DATA WRITES. In many cases we simply don't use the HW busy
>>> detection at all, but instead rely on the mmc core to send CMD13 in a
>>> loop to poll. Well, then if the polling would have consisted of a
>>> couple of CMD13s that wouldn't be an issue, but my observations is
>>> rather that the numbers of CMD13 sent to poll is in the range or
>>> hundreds/thousands - per each WRITE request!
>>>
>>> I am going to send a patch (or two) that improves the behavior. It
>>> might even involve changing parts in core layer, not sure how the end
>>> result will look like yet.
>>>
>>> In any case, I have applied patch 1 and patch2 for next, as the tests
>>> turned out well at my side. I also took the liberty of updating some
>>> of the comments/changelogs, please have look and tell if there is
>>> something you want to change.
>>>
>>> I will continue with the rest of series next week.
>>>
>>> Kind regards
>>> Uffe
>>>

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 5/21/19 9:56 AM, Ulf Hansson wrote:
> On Tue, 21 May 2019 at 09:38, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>> hi Ulf
>>
>> Just a "gentleman ping" about the rest of series.
>> "mmc: mmci: add busy detect for stm32 sdmmc variant"
> 
> Thanks!
> 
> It's been a busy period and I am currently traveling. My plan is to
> look at in detail beginning of next week when get back home. I hope
> that's okay.

yes, I understand, it's just to not forget me :-)

> 
> Kind regards
> Uffe
> 
>>
>> Regards
>> Ludo
>>
>> On 5/3/19 3:29 PM, Ulf Hansson wrote:
>>> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>>>
>>>>
>>>>
>>>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>>>
>>>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>>>
>>>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>>>> Some adaptations are required:
>>>>>> -Avoid to check and poll busy status when is not expected.
>>>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>>>     different.
>>>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>>>
>>>>>> V2:
>>>>>> -mmci_cmd_irq cleanup in separate patch.
>>>>>> -simplify the busy_detect_flag exclude
>>>>>> -replace sdmmc specific comment in
>>>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>>>> to focus on common behavior
>>>>>>
>>>>>> Ludovic Barre (5):
>>>>>>      mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>>>      mmc: mmci: avoid fake busy polling in mmci_irq
>>>>>>      mmc: mmci: fix clear of busy detect status
>>>>>>      mmc: mmci: add hardware busy timeout feature
>>>>>>      mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>>>
>>>>>>     drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>>>     drivers/mmc/host/mmci.h |  3 +++
>>>>>>     2 files changed, 51 insertions(+), 13 deletions(-)
>>>>>>
>>>>>> --
>>>>>> 2.7.4
>>>>>>
>>>>>
>>>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>>>> this series.
>>>>>
>>>>> However, while running some tests on Ux500 for validating the busy
>>>>> detection code, even without your series applied, I encounter some odd
>>>>> behaviors. I am looking into the problem to understand better and will
>>>>> let you know as soon as I have some more data to share.
>>>>
>>>> Oops, don't hesitate to share your status, if I could help.
>>>
>>> Thanks! Good and bad news here, then.
>>>
>>> I now understand what is going on - and there is certainly room for
>>> improvements here, but more importantly the actual mmci busy detection
>>> works as expected.
>>>
>>> When it comes to improvements, the main issue I have found is how we
>>> treat DATA WRITES. In many cases we simply don't use the HW busy
>>> detection at all, but instead rely on the mmc core to send CMD13 in a
>>> loop to poll. Well, then if the polling would have consisted of a
>>> couple of CMD13s that wouldn't be an issue, but my observations is
>>> rather that the numbers of CMD13 sent to poll is in the range or
>>> hundreds/thousands - per each WRITE request!
>>>
>>> I am going to send a patch (or two) that improves the behavior. It
>>> might even involve changing parts in core layer, not sure how the end
>>> result will look like yet.
>>>
>>> In any case, I have applied patch 1 and patch2 for next, as the tests
>>> turned out well at my side. I also took the liberty of updating some
>>> of the comments/changelogs, please have look and tell if there is
>>> something you want to change.
>>>
>>> I will continue with the rest of series next week.
>>>
>>> Kind regards
>>> Uffe
>>>

Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant

[Ludovic BARRE]

On 5/21/19 9:56 AM, Ulf Hansson wrote:
> On Tue, 21 May 2019 at 09:38, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>> hi Ulf
>>
>> Just a "gentleman ping" about the rest of series.
>> "mmc: mmci: add busy detect for stm32 sdmmc variant"
> 
> Thanks!
> 
> It's been a busy period and I am currently traveling. My plan is to
> look at in detail beginning of next week when get back home. I hope
> that's okay.

yes, I understand, it's just to not forget me :-)

> 
> Kind regards
> Uffe
> 
>>
>> Regards
>> Ludo
>>
>> On 5/3/19 3:29 PM, Ulf Hansson wrote:
>>> On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>>>
>>>>
>>>>
>>>> On 4/30/19 1:13 PM, Ulf Hansson wrote:
>>>>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>>>
>>>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>>>
>>>>>> This patch series adds busy detect for stm32 sdmmc variant.
>>>>>> Some adaptations are required:
>>>>>> -Avoid to check and poll busy status when is not expected.
>>>>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are
>>>>>>     different.
>>>>>> -Add hardware busy timeout with MMCIDATATIMER register.
>>>>>>
>>>>>> V2:
>>>>>> -mmci_cmd_irq cleanup in separate patch.
>>>>>> -simplify the busy_detect_flag exclude
>>>>>> -replace sdmmc specific comment in
>>>>>> "mmc: mmci: avoid fake busy polling in mmci_irq"
>>>>>> to focus on common behavior
>>>>>>
>>>>>> Ludovic Barre (5):
>>>>>>      mmc: mmci: cleanup mmci_cmd_irq for busy detect feature
>>>>>>      mmc: mmci: avoid fake busy polling in mmci_irq
>>>>>>      mmc: mmci: fix clear of busy detect status
>>>>>>      mmc: mmci: add hardware busy timeout feature
>>>>>>      mmc: mmci: add busy detect for stm32 sdmmc variant
>>>>>>
>>>>>>     drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++-----------
>>>>>>     drivers/mmc/host/mmci.h |  3 +++
>>>>>>     2 files changed, 51 insertions(+), 13 deletions(-)
>>>>>>
>>>>>> --
>>>>>> 2.7.4
>>>>>>
>>>>>
>>>>> Ludovic, just wanted to let you know that I am reviewing and testing
>>>>> this series.
>>>>>
>>>>> However, while running some tests on Ux500 for validating the busy
>>>>> detection code, even without your series applied, I encounter some odd
>>>>> behaviors. I am looking into the problem to understand better and will
>>>>> let you know as soon as I have some more data to share.
>>>>
>>>> Oops, don't hesitate to share your status, if I could help.
>>>
>>> Thanks! Good and bad news here, then.
>>>
>>> I now understand what is going on - and there is certainly room for
>>> improvements here, but more importantly the actual mmci busy detection
>>> works as expected.
>>>
>>> When it comes to improvements, the main issue I have found is how we
>>> treat DATA WRITES. In many cases we simply don't use the HW busy
>>> detection at all, but instead rely on the mmc core to send CMD13 in a
>>> loop to poll. Well, then if the polling would have consisted of a
>>> couple of CMD13s that wouldn't be an issue, but my observations is
>>> rather that the numbers of CMD13 sent to poll is in the range or
>>> hundreds/thousands - per each WRITE request!
>>>
>>> I am going to send a patch (or two) that improves the behavior. It
>>> might even involve changing parts in core layer, not sure how the end
>>> result will look like yet.
>>>
>>> In any case, I have applied patch 1 and patch2 for next, as the tests
>>> turned out well at my side. I also took the liberty of updating some
>>> of the comments/changelogs, please have look and tell if there is
>>> something you want to change.
>>>
>>> I will continue with the rest of series next week.
>>>
>>> Kind regards
>>> Uffe
>>>

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Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ulf Hansson]

On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> The "busy_detect_flag" is used to read/clear busy value of
> mmci status. The "busy_detect_mask" is used to manage busy irq of
> mmci mask.
> For sdmmc variant, the 2 properties have not the same offset.
> To clear the busyd0 status bit, we must add busy detect flag,
> the mmci mask is not enough.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>

Ludovic, again, apologies for the delay.

> ---
>  drivers/mmc/host/mmci.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index a040f54..3cd52e8 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>                  * to make sure that both start and end interrupts are always
>                  * cleared one after the other.
>                  */
> -               status &= readl(host->base + MMCIMASK0);
> +               status &= readl(host->base + MMCIMASK0) |
> +                       host->variant->busy_detect_flag;

I think this is not entirely correct, because it would mean we check
for busy even if we haven't unmasked the busy IRQ via the
variant->busy_detect_mask.

I suggest to store a new bool in the host (call it
"busy_detect_unmasked" or whatever makes sense to you), to track
whether we have unmasked the busy IRQ or not. Then take this flag into
account, before ORing the value of host->variant->busy_detect_flag,
according to above.

>                 if (host->variant->busy_detect)
>                         writel(status & ~host->variant->busy_detect_mask,
>                                host->base + MMCICLEAR);
> --
> 2.7.4
>

Kind regards
Uffe

Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ulf Hansson]

On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> The "busy_detect_flag" is used to read/clear busy value of
> mmci status. The "busy_detect_mask" is used to manage busy irq of
> mmci mask.
> For sdmmc variant, the 2 properties have not the same offset.
> To clear the busyd0 status bit, we must add busy detect flag,
> the mmci mask is not enough.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>

Ludovic, again, apologies for the delay.

> ---
>  drivers/mmc/host/mmci.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index a040f54..3cd52e8 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>                  * to make sure that both start and end interrupts are always
>                  * cleared one after the other.
>                  */
> -               status &= readl(host->base + MMCIMASK0);
> +               status &= readl(host->base + MMCIMASK0) |
> +                       host->variant->busy_detect_flag;

I think this is not entirely correct, because it would mean we check
for busy even if we haven't unmasked the busy IRQ via the
variant->busy_detect_mask.

I suggest to store a new bool in the host (call it
"busy_detect_unmasked" or whatever makes sense to you), to track
whether we have unmasked the busy IRQ or not. Then take this flag into
account, before ORing the value of host->variant->busy_detect_flag,
according to above.

>                 if (host->variant->busy_detect)
>                         writel(status & ~host->variant->busy_detect_mask,
>                                host->base + MMCICLEAR);
> --
> 2.7.4
>

Kind regards
Uffe

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Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic BARRE]

hi Ulf

On 5/27/19 8:17 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> The "busy_detect_flag" is used to read/clear busy value of
>> mmci status. The "busy_detect_mask" is used to manage busy irq of
>> mmci mask.
>> For sdmmc variant, the 2 properties have not the same offset.
>> To clear the busyd0 status bit, we must add busy detect flag,
>> the mmci mask is not enough.
>>
>> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> 
> Ludovic, again, apologies for the delay.
> 
>> ---
>>   drivers/mmc/host/mmci.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
>> index a040f54..3cd52e8 100644
>> --- a/drivers/mmc/host/mmci.c
>> +++ b/drivers/mmc/host/mmci.c
>> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>>                   * to make sure that both start and end interrupts are always
>>                   * cleared one after the other.
>>                   */
>> -               status &= readl(host->base + MMCIMASK0);
>> +               status &= readl(host->base + MMCIMASK0) |
>> +                       host->variant->busy_detect_flag;
> 
> I think this is not entirely correct, because it would mean we check
> for busy even if we haven't unmasked the busy IRQ via the
> variant->busy_detect_mask.

if the variant is busy_detect false:
  => no problem because the busy_detect_flag or busy_detect_mask is not
     defined.

if variant is busy_detect true:
the busy handle is split in 3 steps (see mmci_cmd_irq):
step 1: detection of busy line => unmasked the busy irq end
step 2: in busy wait => ignore cmd irq while current busy flag is
enabled.
step 3: end of busy => clear and mask busy irq

To detect the first step (see mmci_cmd_irq: which unmasks the busy irq)
we need to know the current busy state. Actually, the status register is
re-read in mmci_cmd_irq, why not used the status read in mmci_irq and in
parameter ?

Regards,
Ludo

> 
> I suggest to store a new bool in the host (call it
> "busy_detect_unmasked" or whatever makes sense to you), to track
> whether we have unmasked the busy IRQ or not. Then take this flag into
> account, before ORing the value of host->variant->busy_detect_flag,
> according to above.
> 
>>                  if (host->variant->busy_detect)
>>                          writel(status & ~host->variant->busy_detect_mask,
>>                                 host->base + MMCICLEAR);
>> --
>> 2.7.4
>>
> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic BARRE]

hi Ulf

On 5/27/19 8:17 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> The "busy_detect_flag" is used to read/clear busy value of
>> mmci status. The "busy_detect_mask" is used to manage busy irq of
>> mmci mask.
>> For sdmmc variant, the 2 properties have not the same offset.
>> To clear the busyd0 status bit, we must add busy detect flag,
>> the mmci mask is not enough.
>>
>> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> 
> Ludovic, again, apologies for the delay.
> 
>> ---
>>   drivers/mmc/host/mmci.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
>> index a040f54..3cd52e8 100644
>> --- a/drivers/mmc/host/mmci.c
>> +++ b/drivers/mmc/host/mmci.c
>> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>>                   * to make sure that both start and end interrupts are always
>>                   * cleared one after the other.
>>                   */
>> -               status &= readl(host->base + MMCIMASK0);
>> +               status &= readl(host->base + MMCIMASK0) |
>> +                       host->variant->busy_detect_flag;
> 
> I think this is not entirely correct, because it would mean we check
> for busy even if we haven't unmasked the busy IRQ via the
> variant->busy_detect_mask.

if the variant is busy_detect false:
  => no problem because the busy_detect_flag or busy_detect_mask is not
     defined.

if variant is busy_detect true:
the busy handle is split in 3 steps (see mmci_cmd_irq):
step 1: detection of busy line => unmasked the busy irq end
step 2: in busy wait => ignore cmd irq while current busy flag is
enabled.
step 3: end of busy => clear and mask busy irq

To detect the first step (see mmci_cmd_irq: which unmasks the busy irq)
we need to know the current busy state. Actually, the status register is
re-read in mmci_cmd_irq, why not used the status read in mmci_irq and in
parameter ?

Regards,
Ludo

> 
> I suggest to store a new bool in the host (call it
> "busy_detect_unmasked" or whatever makes sense to you), to track
> whether we have unmasked the busy IRQ or not. Then take this flag into
> account, before ORing the value of host->variant->busy_detect_flag,
> according to above.
> 
>>                  if (host->variant->busy_detect)
>>                          writel(status & ~host->variant->busy_detect_mask,
>>                                 host->base + MMCICLEAR);
>> --
>> 2.7.4
>>
> 
> Kind regards
> Uffe
> 

Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ludovic BARRE]

hi Ulf

On 5/27/19 8:17 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> The "busy_detect_flag" is used to read/clear busy value of
>> mmci status. The "busy_detect_mask" is used to manage busy irq of
>> mmci mask.
>> For sdmmc variant, the 2 properties have not the same offset.
>> To clear the busyd0 status bit, we must add busy detect flag,
>> the mmci mask is not enough.
>>
>> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> 
> Ludovic, again, apologies for the delay.
> 
>> ---
>>   drivers/mmc/host/mmci.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
>> index a040f54..3cd52e8 100644
>> --- a/drivers/mmc/host/mmci.c
>> +++ b/drivers/mmc/host/mmci.c
>> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>>                   * to make sure that both start and end interrupts are always
>>                   * cleared one after the other.
>>                   */
>> -               status &= readl(host->base + MMCIMASK0);
>> +               status &= readl(host->base + MMCIMASK0) |
>> +                       host->variant->busy_detect_flag;
> 
> I think this is not entirely correct, because it would mean we check
> for busy even if we haven't unmasked the busy IRQ via the
> variant->busy_detect_mask.

if the variant is busy_detect false:
  => no problem because the busy_detect_flag or busy_detect_mask is not
     defined.

if variant is busy_detect true:
the busy handle is split in 3 steps (see mmci_cmd_irq):
step 1: detection of busy line => unmasked the busy irq end
step 2: in busy wait => ignore cmd irq while current busy flag is
enabled.
step 3: end of busy => clear and mask busy irq

To detect the first step (see mmci_cmd_irq: which unmasks the busy irq)
we need to know the current busy state. Actually, the status register is
re-read in mmci_cmd_irq, why not used the status read in mmci_irq and in
parameter ?

Regards,
Ludo

> 
> I suggest to store a new bool in the host (call it
> "busy_detect_unmasked" or whatever makes sense to you), to track
> whether we have unmasked the busy IRQ or not. Then take this flag into
> account, before ORing the value of host->variant->busy_detect_flag,
> according to above.
> 
>>                  if (host->variant->busy_detect)
>>                          writel(status & ~host->variant->busy_detect_mask,
>>                                 host->base + MMCICLEAR);
>> --
>> 2.7.4
>>
> 
> Kind regards
> Uffe
> 

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Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ulf Hansson]

On Wed, 29 May 2019 at 11:20, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
> hi Ulf
>
> On 5/27/19 8:17 PM, Ulf Hansson wrote:
> > On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>
> >> From: Ludovic Barre <ludovic.barre@st.com>
> >>
> >> The "busy_detect_flag" is used to read/clear busy value of
> >> mmci status. The "busy_detect_mask" is used to manage busy irq of
> >> mmci mask.
> >> For sdmmc variant, the 2 properties have not the same offset.
> >> To clear the busyd0 status bit, we must add busy detect flag,
> >> the mmci mask is not enough.
> >>
> >> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> >
> > Ludovic, again, apologies for the delay.
> >
> >> ---
> >>   drivers/mmc/host/mmci.c | 3 ++-
> >>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> >> index a040f54..3cd52e8 100644
> >> --- a/drivers/mmc/host/mmci.c
> >> +++ b/drivers/mmc/host/mmci.c
> >> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
> >>                   * to make sure that both start and end interrupts are always
> >>                   * cleared one after the other.
> >>                   */
> >> -               status &= readl(host->base + MMCIMASK0);
> >> +               status &= readl(host->base + MMCIMASK0) |
> >> +                       host->variant->busy_detect_flag;
> >
> > I think this is not entirely correct, because it would mean we check
> > for busy even if we haven't unmasked the busy IRQ via the
> > variant->busy_detect_mask.
>
> if the variant is busy_detect false:
>   => no problem because the busy_detect_flag or busy_detect_mask is not
>      defined.

Right.

>
> if variant is busy_detect true:
> the busy handle is split in 3 steps (see mmci_cmd_irq):
> step 1: detection of busy line => unmasked the busy irq end
> step 2: in busy wait => ignore cmd irq while current busy flag is
> enabled.
> step 3: end of busy => clear and mask busy irq
>
> To detect the first step (see mmci_cmd_irq: which unmasks the busy irq)
> we need to know the current busy state. Actually, the status register is
> re-read in mmci_cmd_irq, why not used the status read in mmci_irq and in
> parameter ?

Right, I see your point.

On the other hand, that re-read of the status registers should really
not be needed. Maybe it's a leftover from my initial version of the
code, but in any case we should remove that.

>
> Regards,
> Ludo
>
> >
> > I suggest to store a new bool in the host (call it
> > "busy_detect_unmasked" or whatever makes sense to you), to track
> > whether we have unmasked the busy IRQ or not. Then take this flag into
> > account, before ORing the value of host->variant->busy_detect_flag,
> > according to above.
> >
> >>                  if (host->variant->busy_detect)
> >>                          writel(status & ~host->variant->busy_detect_mask,
> >>                                 host->base + MMCICLEAR);
> >> --
> >> 2.7.4

Kind regards
Uffe

Re: [PATCH V2 3/5] mmc: mmci: fix clear of busy detect status

[Ulf Hansson]

On Wed, 29 May 2019 at 11:20, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
> hi Ulf
>
> On 5/27/19 8:17 PM, Ulf Hansson wrote:
> > On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote:
> >>
> >> From: Ludovic Barre <ludovic.barre@st.com>
> >>
> >> The "busy_detect_flag" is used to read/clear busy value of
> >> mmci status. The "busy_detect_mask" is used to manage busy irq of
> >> mmci mask.
> >> For sdmmc variant, the 2 properties have not the same offset.
> >> To clear the busyd0 status bit, we must add busy detect flag,
> >> the mmci mask is not enough.
> >>
> >> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> >
> > Ludovic, again, apologies for the delay.
> >
> >> ---
> >>   drivers/mmc/host/mmci.c | 3 ++-
> >>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> >> index a040f54..3cd52e8 100644
> >> --- a/drivers/mmc/host/mmci.c
> >> +++ b/drivers/mmc/host/mmci.c
> >> @@ -1517,7 +1517,8 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
> >>                   * to make sure that both start and end interrupts are always
> >>                   * cleared one after the other.
> >>                   */
> >> -               status &= readl(host->base + MMCIMASK0);
> >> +               status &= readl(host->base + MMCIMASK0) |
> >> +                       host->variant->busy_detect_flag;
> >
> > I think this is not entirely correct, because it would mean we check
> > for busy even if we haven't unmasked the busy IRQ via the
> > variant->busy_detect_mask.
>
> if the variant is busy_detect false:
>   => no problem because the busy_detect_flag or busy_detect_mask is not
>      defined.

Right.

>
> if variant is busy_detect true:
> the busy handle is split in 3 steps (see mmci_cmd_irq):
> step 1: detection of busy line => unmasked the busy irq end
> step 2: in busy wait => ignore cmd irq while current busy flag is
> enabled.
> step 3: end of busy => clear and mask busy irq
>
> To detect the first step (see mmci_cmd_irq: which unmasks the busy irq)
> we need to know the current busy state. Actually, the status register is
> re-read in mmci_cmd_irq, why not used the status read in mmci_irq and in
> parameter ?

Right, I see your point.

On the other hand, that re-read of the status registers should really
not be needed. Maybe it's a leftover from my initial version of the
code, but in any case we should remove that.

>
> Regards,
> Ludo
>
> >
> > I suggest to store a new bool in the host (call it
> > "busy_detect_unmasked" or whatever makes sense to you), to track
> > whether we have unmasked the busy IRQ or not. Then take this flag into
> > account, before ORing the value of host->variant->busy_detect_flag,
> > according to above.
> >
> >>                  if (host->variant->busy_detect)
> >>                          writel(status & ~host->variant->busy_detect_mask,
> >>                                 host->base + MMCICLEAR);
> >> --
> >> 2.7.4

Kind regards
Uffe

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