[PATCH V1 1/6] i2c: tegra: clean up macros

[PATCH V1 1/6] i2c: tegra: clean up macros

[Bitan Biswas]

Clean up macros by:
1) removing unused macros
2) replace constants by macro BIT()

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 1dbba39..00692d8 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -54,20 +54,15 @@
 #define I2C_INT_STATUS				0x068
 #define I2C_INT_BUS_CLR_DONE			BIT(11)
 #define I2C_INT_PACKET_XFER_COMPLETE		BIT(7)
-#define I2C_INT_ALL_PACKETS_XFER_COMPLETE	BIT(6)
-#define I2C_INT_TX_FIFO_OVERFLOW		BIT(5)
-#define I2C_INT_RX_FIFO_UNDERFLOW		BIT(4)
 #define I2C_INT_NO_ACK				BIT(3)
 #define I2C_INT_ARBITRATION_LOST		BIT(2)
 #define I2C_INT_TX_FIFO_DATA_REQ		BIT(1)
 #define I2C_INT_RX_FIFO_DATA_REQ		BIT(0)
 #define I2C_CLK_DIVISOR				0x06c
 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT	16
-#define I2C_CLK_MULTIPLIER_STD_FAST_MODE	8
 
 #define DVC_CTRL_REG1				0x000
 #define DVC_CTRL_REG1_INTR_EN			BIT(10)
-#define DVC_CTRL_REG2				0x004
 #define DVC_CTRL_REG3				0x008
 #define DVC_CTRL_REG3_SW_PROG			BIT(26)
 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN		BIT(30)
@@ -75,24 +70,21 @@
 #define DVC_STATUS_I2C_DONE_INTR		BIT(30)
 
 #define I2C_ERR_NONE				0x00
-#define I2C_ERR_NO_ACK				0x01
-#define I2C_ERR_ARBITRATION_LOST		0x02
-#define I2C_ERR_UNKNOWN_INTERRUPT		0x04
+#define I2C_ERR_NO_ACK				BIT(0)
+#define I2C_ERR_ARBITRATION_LOST		BIT(1)
+#define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
 
 #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
 #define PACKET_HEADER0_PACKET_ID_SHIFT		16
 #define PACKET_HEADER0_CONT_ID_SHIFT		12
 #define PACKET_HEADER0_PROTOCOL_I2C		BIT(4)
 
-#define I2C_HEADER_HIGHSPEED_MODE		BIT(22)
 #define I2C_HEADER_CONT_ON_NAK			BIT(21)
-#define I2C_HEADER_SEND_START_BYTE		BIT(20)
 #define I2C_HEADER_READ				BIT(19)
 #define I2C_HEADER_10BIT_ADDR			BIT(18)
 #define I2C_HEADER_IE_ENABLE			BIT(17)
 #define I2C_HEADER_REPEAT_START			BIT(16)
 #define I2C_HEADER_CONTINUE_XFER		BIT(15)
-#define I2C_HEADER_MASTER_ADDR_SHIFT		12
 #define I2C_HEADER_SLAVE_ADDR_SHIFT		1
 
 #define I2C_BUS_CLEAR_CNFG			0x084
@@ -106,8 +98,6 @@
 
 #define I2C_CONFIG_LOAD				0x08C
 #define I2C_MSTR_CONFIG_LOAD			BIT(0)
-#define I2C_SLV_CONFIG_LOAD			BIT(1)
-#define I2C_TIMEOUT_CONFIG_LOAD			BIT(2)
 
 #define I2C_CLKEN_OVERRIDE			0x090
 #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
@@ -133,7 +123,6 @@
 #define I2C_STANDARD_MODE			100000
 #define I2C_FAST_MODE				400000
 #define I2C_FAST_PLUS_MODE			1000000
-#define I2C_HS_MODE				3500000
 
 /* Packet header size in bytes */
 #define I2C_PACKET_HEADER_SIZE			12
-- 
2.7.4

[PATCH V1 2/6] i2c: tegra: remove unnecessary variable init

[Bitan Biswas]

Remove variable initializations in functions that
are followed by assignments before use

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 00692d8..f7116b7 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -689,7 +689,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
 	u32 val;
 	int err;
 	u32 clk_divisor, clk_multiplier;
-	u32 tsu_thd = 0;
+	u32 tsu_thd;
 	u8 tlow, thigh;
 
 	err = pm_runtime_get_sync(i2c_dev->dev);
@@ -1218,7 +1218,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 {
 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
 	int i;
-	int ret = 0;
+	int ret;
 
 	ret = pm_runtime_get_sync(i2c_dev->dev);
 	if (ret < 0) {
@@ -1489,7 +1489,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	void __iomem *base;
 	phys_addr_t base_phys;
 	int irq;
-	int ret = 0;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base_phys = res->start;
-- 
2.7.4

[PATCH V1 3/6] i2c: tegra: fix alignment and spacing violations

[Bitan Biswas]

Fix checkpatch.pl alignment and blank line check(s) in i2c-tegra.c

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index f7116b7..2d381de 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -295,7 +295,7 @@ static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
  * to the I2C block inside the DVC block
  */
 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
-	unsigned long reg)
+					unsigned long reg)
 {
 	if (i2c_dev->is_dvc)
 		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
@@ -303,7 +303,7 @@ static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
 }
 
 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
-	unsigned long reg)
+		       unsigned long reg)
 {
 	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
 
@@ -318,13 +318,13 @@ static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
 }
 
 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
-	unsigned long reg, int len)
+			unsigned long reg, int len)
 {
 	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
 }
 
 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
-	unsigned long reg, int len)
+		       unsigned long reg, int len)
 {
 	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
 }
@@ -669,10 +669,11 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
 		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
 		if (in_interrupt())
 			err = readl_poll_timeout_atomic(addr, val, val == 0,
-					1000, I2C_CONFIG_LOAD_TIMEOUT);
+							1000,
+							I2C_CONFIG_LOAD_TIMEOUT);
 		else
-			err = readl_poll_timeout(addr, val, val == 0,
-					1000, I2C_CONFIG_LOAD_TIMEOUT);
+			err = readl_poll_timeout(addr, val, val == 0, 1000,
+						 I2C_CONFIG_LOAD_TIMEOUT);
 
 		if (err) {
 			dev_warn(i2c_dev->dev,
@@ -1013,7 +1014,8 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
 }
 
 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
-	struct i2c_msg *msg, enum msg_end_type end_state)
+			      struct i2c_msg *msg,
+			      enum msg_end_type end_state)
 {
 	u32 packet_header;
 	u32 int_mask;
@@ -1150,9 +1152,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 		if (err)
 			return err;
 
-		time_left = wait_for_completion_timeout(
-						&i2c_dev->dma_complete,
-						msecs_to_jiffies(xfer_time));
+		time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
+							msecs_to_jiffies(xfer_time));
 		if (time_left == 0) {
 			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
 			dmaengine_terminate_sync(i2c_dev->msg_read ?
@@ -1214,7 +1215,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 }
 
 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
-	int num)
+			  int num)
 {
 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
 	int i;
@@ -1260,14 +1261,15 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
 {
 	struct device_node *np = i2c_dev->dev->of_node;
 	int ret;
+	bool multi_mode;
 
 	ret = of_property_read_u32(np, "clock-frequency",
-			&i2c_dev->bus_clk_rate);
+				   &i2c_dev->bus_clk_rate);
 	if (ret)
 		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
 
-	i2c_dev->is_multimaster_mode = of_property_read_bool(np,
-			"multi-master");
+	multi_mode = of_property_read_bool(np, "multi-master");
+	i2c_dev->is_multimaster_mode = multi_mode;
 }
 
 static const struct i2c_algorithm tegra_i2c_algo = {
@@ -1611,7 +1613,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	}
 
 	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
-			tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
+			       tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
 		goto release_dma;
@@ -1704,6 +1706,7 @@ static const struct dev_pm_ops tegra_i2c_pm = {
 	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
 			   NULL)
 };
+
 #define TEGRA_I2C_PM	(&tegra_i2c_pm)
 #else
 #define TEGRA_I2C_PM	NULL
-- 
2.7.4

[PATCH V1 4/6] i2c: tegra: add spinlock definition comment

[Bitan Biswas]

Fix checkpatch.pl CHECK as follows:
CHECK: spinlock_t definition without comment
+       spinlock_t xfer_lock;

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 2d381de..bececa6 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -269,6 +269,7 @@ struct tegra_i2c_dev {
 	u32 bus_clk_rate;
 	u16 clk_divisor_non_hs_mode;
 	bool is_multimaster_mode;
+	/* xfer_lock: lock to serialize transfer submission and processing */
 	spinlock_t xfer_lock;
 	struct dma_chan *tx_dma_chan;
 	struct dma_chan *rx_dma_chan;
-- 
2.7.4

[PATCH V1 5/6] i2c: tegra: fix msleep warning

[Bitan Biswas]

Fix checkpatch.pl WARNING for delay of approximately 1msec
in flush i2c FIFO polling loop by using usleep_range(1000, 2000):
WARNING: msleep < 20ms can sleep for up to 20ms; see ...
Documentation/timers/timers-howto.txt
+               msleep(1);

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index bececa6..4dfb4c1 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -476,7 +476,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
 			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
 			return -ETIMEDOUT;
 		}
-		msleep(1);
+		usleep_range(1000, 2000);
 	}
 	return 0;
 }
-- 
2.7.4

[PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Bitan Biswas]

Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
as needed. Replace BUG() with error handling code.
Define I2C_ERR_UNEXPECTED_STATUS for error handling.

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 4dfb4c1..c407bd7 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -73,6 +73,7 @@
 #define I2C_ERR_NO_ACK				BIT(0)
 #define I2C_ERR_ARBITRATION_LOST		BIT(1)
 #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
+#define I2C_ERR_UNEXPECTED_STATUS		BIT(3)
 
 #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
 #define PACKET_HEADER0_PACKET_ID_SHIFT		16
@@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 	 * prevent overwriting past the end of buf
 	 */
 	if (rx_fifo_avail > 0 && buf_remaining > 0) {
-		BUG_ON(buf_remaining > 3);
 		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
 		val = cpu_to_le32(val);
 		memcpy(buf, &val, buf_remaining);
@@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 		rx_fifo_avail--;
 	}
 
-	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
 	i2c_dev->msg_buf_remaining = buf_remaining;
 	i2c_dev->msg_buf = buf;
 
@@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
 	 * boundary and fault.
 	 */
 	if (tx_fifo_avail > 0 && buf_remaining > 0) {
-		BUG_ON(buf_remaining > 3);
 		memcpy(&val, buf, buf_remaining);
 		val = le32_to_cpu(val);
 
@@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 
 	if (!i2c_dev->is_curr_dma_xfer) {
 		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
-			if (i2c_dev->msg_buf_remaining)
+			if (i2c_dev->msg_buf_remaining) {
 				tegra_i2c_empty_rx_fifo(i2c_dev);
-			else
-				BUG();
+			} else {
+				dev_err(i2c_dev->dev, "unexpected rx data request\n");
+				i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
+				goto err;
+			}
 		}
 
 		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
@@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
 		if (i2c_dev->is_curr_dma_xfer)
 			i2c_dev->msg_buf_remaining = 0;
-		BUG_ON(i2c_dev->msg_buf_remaining);
+		WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
 		complete(&i2c_dev->msg_complete);
 	}
 	goto done;
-- 
2.7.4

Re: [PATCH V1 1/6] i2c: tegra: clean up macros

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Clean up macros by:
> 1) removing unused macros
> 2) replace constants by macro BIT()
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 17 +++--------------
>  1 file changed, 3 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 1dbba39..00692d8 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -54,20 +54,15 @@
>  #define I2C_INT_STATUS				0x068
>  #define I2C_INT_BUS_CLR_DONE			BIT(11)
>  #define I2C_INT_PACKET_XFER_COMPLETE		BIT(7)
> -#define I2C_INT_ALL_PACKETS_XFER_COMPLETE	BIT(6)
> -#define I2C_INT_TX_FIFO_OVERFLOW		BIT(5)
> -#define I2C_INT_RX_FIFO_UNDERFLOW		BIT(4)
>  #define I2C_INT_NO_ACK				BIT(3)
>  #define I2C_INT_ARBITRATION_LOST		BIT(2)
>  #define I2C_INT_TX_FIFO_DATA_REQ		BIT(1)
>  #define I2C_INT_RX_FIFO_DATA_REQ		BIT(0)
>  #define I2C_CLK_DIVISOR				0x06c
>  #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT	16
> -#define I2C_CLK_MULTIPLIER_STD_FAST_MODE	8
>  
>  #define DVC_CTRL_REG1				0x000
>  #define DVC_CTRL_REG1_INTR_EN			BIT(10)
> -#define DVC_CTRL_REG2				0x004
>  #define DVC_CTRL_REG3				0x008
>  #define DVC_CTRL_REG3_SW_PROG			BIT(26)
>  #define DVC_CTRL_REG3_I2C_DONE_INTR_EN		BIT(30)
> @@ -75,24 +70,21 @@
>  #define DVC_STATUS_I2C_DONE_INTR		BIT(30)
>  
>  #define I2C_ERR_NONE				0x00
> -#define I2C_ERR_NO_ACK				0x01
> -#define I2C_ERR_ARBITRATION_LOST		0x02
> -#define I2C_ERR_UNKNOWN_INTERRUPT		0x04
> +#define I2C_ERR_NO_ACK				BIT(0)
> +#define I2C_ERR_ARBITRATION_LOST		BIT(1)
> +#define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
>  
>  #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
>  #define PACKET_HEADER0_PACKET_ID_SHIFT		16
>  #define PACKET_HEADER0_CONT_ID_SHIFT		12
>  #define PACKET_HEADER0_PROTOCOL_I2C		BIT(4)
>  
> -#define I2C_HEADER_HIGHSPEED_MODE		BIT(22)
>  #define I2C_HEADER_CONT_ON_NAK			BIT(21)
> -#define I2C_HEADER_SEND_START_BYTE		BIT(20)
>  #define I2C_HEADER_READ				BIT(19)
>  #define I2C_HEADER_10BIT_ADDR			BIT(18)
>  #define I2C_HEADER_IE_ENABLE			BIT(17)
>  #define I2C_HEADER_REPEAT_START			BIT(16)
>  #define I2C_HEADER_CONTINUE_XFER		BIT(15)
> -#define I2C_HEADER_MASTER_ADDR_SHIFT		12
>  #define I2C_HEADER_SLAVE_ADDR_SHIFT		1
>  
>  #define I2C_BUS_CLEAR_CNFG			0x084
> @@ -106,8 +98,6 @@
>  
>  #define I2C_CONFIG_LOAD				0x08C
>  #define I2C_MSTR_CONFIG_LOAD			BIT(0)
> -#define I2C_SLV_CONFIG_LOAD			BIT(1)
> -#define I2C_TIMEOUT_CONFIG_LOAD			BIT(2)
>  
>  #define I2C_CLKEN_OVERRIDE			0x090
>  #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
> @@ -133,7 +123,6 @@
>  #define I2C_STANDARD_MODE			100000
>  #define I2C_FAST_MODE				400000
>  #define I2C_FAST_PLUS_MODE			1000000
> -#define I2C_HS_MODE				3500000
>  
>  /* Packet header size in bytes */
>  #define I2C_PACKET_HEADER_SIZE			12
> 

Looks good!

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 2/6] i2c: tegra: remove unnecessary variable init

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Remove variable initializations in functions that
> are followed by assignments before use
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 00692d8..f7116b7 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -689,7 +689,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
>  	u32 val;
>  	int err;
>  	u32 clk_divisor, clk_multiplier;
> -	u32 tsu_thd = 0;
> +	u32 tsu_thd;
>  	u8 tlow, thigh;
>  
>  	err = pm_runtime_get_sync(i2c_dev->dev);
> @@ -1218,7 +1218,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
>  {
>  	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
>  	int i;
> -	int ret = 0;
> +	int ret;
>  
>  	ret = pm_runtime_get_sync(i2c_dev->dev);
>  	if (ret < 0) {
> @@ -1489,7 +1489,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
>  	void __iomem *base;
>  	phys_addr_t base_phys;
>  	int irq;
> -	int ret = 0;
> +	int ret;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	base_phys = res->start;
> 

Thanks!

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 3/6] i2c: tegra: fix alignment and spacing violations

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Fix checkpatch.pl alignment and blank line check(s) in i2c-tegra.c
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 35 +++++++++++++++++++----------------
>  1 file changed, 19 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index f7116b7..2d381de 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -295,7 +295,7 @@ static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
>   * to the I2C block inside the DVC block
>   */
>  static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
> -	unsigned long reg)
> +					unsigned long reg)
>  {
>  	if (i2c_dev->is_dvc)
>  		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
> @@ -303,7 +303,7 @@ static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
>  }
>  
>  static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
> -	unsigned long reg)
> +		       unsigned long reg)
>  {
>  	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
>  
> @@ -318,13 +318,13 @@ static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
>  }
>  
>  static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
> -	unsigned long reg, int len)
> +			unsigned long reg, int len)
>  {
>  	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
>  }
>  
>  static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
> -	unsigned long reg, int len)
> +		       unsigned long reg, int len)
>  {
>  	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
>  }
> @@ -669,10 +669,11 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
>  		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
>  		if (in_interrupt())
>  			err = readl_poll_timeout_atomic(addr, val, val == 0,
> -					1000, I2C_CONFIG_LOAD_TIMEOUT);
> +							1000,
> +							I2C_CONFIG_LOAD_TIMEOUT);
>  		else
> -			err = readl_poll_timeout(addr, val, val == 0,
> -					1000, I2C_CONFIG_LOAD_TIMEOUT);
> +			err = readl_poll_timeout(addr, val, val == 0, 1000,
> +						 I2C_CONFIG_LOAD_TIMEOUT);
>  
>  		if (err) {
>  			dev_warn(i2c_dev->dev,
> @@ -1013,7 +1014,8 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
>  }
>  
>  static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
> -	struct i2c_msg *msg, enum msg_end_type end_state)
> +			      struct i2c_msg *msg,
> +			      enum msg_end_type end_state)
>  {
>  	u32 packet_header;
>  	u32 int_mask;
> @@ -1150,9 +1152,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
>  		if (err)
>  			return err;
>  
> -		time_left = wait_for_completion_timeout(
> -						&i2c_dev->dma_complete,
> -						msecs_to_jiffies(xfer_time));
> +		time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
> +							msecs_to_jiffies(xfer_time));
>  		if (time_left == 0) {
>  			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
>  			dmaengine_terminate_sync(i2c_dev->msg_read ?
> @@ -1214,7 +1215,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
>  }
>  
>  static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
> -	int num)
> +			  int num)
>  {
>  	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
>  	int i;
> @@ -1260,14 +1261,15 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
>  {
>  	struct device_node *np = i2c_dev->dev->of_node;
>  	int ret;
> +	bool multi_mode;
>  
>  	ret = of_property_read_u32(np, "clock-frequency",
> -			&i2c_dev->bus_clk_rate);
> +				   &i2c_dev->bus_clk_rate);
>  	if (ret)
>  		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
>  
> -	i2c_dev->is_multimaster_mode = of_property_read_bool(np,
> -			"multi-master");
> +	multi_mode = of_property_read_bool(np, "multi-master");
> +	i2c_dev->is_multimaster_mode = multi_mode;
>  }
>  
>  static const struct i2c_algorithm tegra_i2c_algo = {
> @@ -1611,7 +1613,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
>  	}
>  
>  	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
> -			tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
> +			       tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
>  		goto release_dma;
> @@ -1704,6 +1706,7 @@ static const struct dev_pm_ops tegra_i2c_pm = {
>  	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
>  			   NULL)
>  };
> +
>  #define TEGRA_I2C_PM	(&tegra_i2c_pm)
>  #else
>  #define TEGRA_I2C_PM	NULL
> 
Very nice!

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 4/6] i2c: tegra: add spinlock definition comment

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Fix checkpatch.pl CHECK as follows:
> CHECK: spinlock_t definition without comment
> +       spinlock_t xfer_lock;
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 2d381de..bececa6 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -269,6 +269,7 @@ struct tegra_i2c_dev {
>  	u32 bus_clk_rate;
>  	u16 clk_divisor_non_hs_mode;
>  	bool is_multimaster_mode;
> +	/* xfer_lock: lock to serialize transfer submission and processing */
>  	spinlock_t xfer_lock;
>  	struct dma_chan *tx_dma_chan;
>  	struct dma_chan *rx_dma_chan;
> 

Thanks!

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 5/6] i2c: tegra: fix msleep warning

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Fix checkpatch.pl WARNING for delay of approximately 1msec
> in flush i2c FIFO polling loop by using usleep_range(1000, 2000):
> WARNING: msleep < 20ms can sleep for up to 20ms; see ...
> Documentation/timers/timers-howto.txt
> +               msleep(1);
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index bececa6..4dfb4c1 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -476,7 +476,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
>  			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
>  			return -ETIMEDOUT;
>  		}
> -		msleep(1);
> +		usleep_range(1000, 2000);
>  	}
>  	return 0;
>  }
> 

Awesome!

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Dmitry Osipenko]

07.06.2019 14:55, Bitan Biswas пишет:
> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
> as needed. Replace BUG() with error handling code.
> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
> 
> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 4dfb4c1..c407bd7 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -73,6 +73,7 @@
>  #define I2C_ERR_NO_ACK				BIT(0)
>  #define I2C_ERR_ARBITRATION_LOST		BIT(1)
>  #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
> +#define I2C_ERR_UNEXPECTED_STATUS		BIT(3)
>  
>  #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
>  #define PACKET_HEADER0_PACKET_ID_SHIFT		16
> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>  	 * prevent overwriting past the end of buf
>  	 */
>  	if (rx_fifo_avail > 0 && buf_remaining > 0) {
> -		BUG_ON(buf_remaining > 3);
>  		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>  		val = cpu_to_le32(val);
>  		memcpy(buf, &val, buf_remaining);
> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>  		rx_fifo_avail--;
>  	}
>  
> -	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>  	i2c_dev->msg_buf_remaining = buf_remaining;
>  	i2c_dev->msg_buf = buf;
>  
> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
>  	 * boundary and fault.
>  	 */
>  	if (tx_fifo_avail > 0 && buf_remaining > 0) {
> -		BUG_ON(buf_remaining > 3);
>  		memcpy(&val, buf, buf_remaining);
>  		val = le32_to_cpu(val);
>  
> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>  
>  	if (!i2c_dev->is_curr_dma_xfer) {
>  		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
> -			if (i2c_dev->msg_buf_remaining)
> +			if (i2c_dev->msg_buf_remaining) {
>  				tegra_i2c_empty_rx_fifo(i2c_dev);
> -			else
> -				BUG();
> +			} else {
> +				dev_err(i2c_dev->dev, "unexpected rx data request\n");
> +				i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
> +				goto err;
> +			}
>  		}
>  
>  		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
> @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>  	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>  		if (i2c_dev->is_curr_dma_xfer)
>  			i2c_dev->msg_buf_remaining = 0;
> -		BUG_ON(i2c_dev->msg_buf_remaining);
> +		WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>  		complete(&i2c_dev->msg_complete);
>  	}
>  	goto done;
> 

Very nice, thank you very much! BTW, I think it may worth to add another
patch that will reset hardware state in a case of the warning since we
know that something gone wrong.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Dmitry Osipenko]

07.06.2019 15:08, Dmitry Osipenko пишет:
> 07.06.2019 14:55, Bitan Biswas пишет:
>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>> as needed. Replace BUG() with error handling code.
>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>
>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>> ---
>>  drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>>  1 file changed, 8 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index 4dfb4c1..c407bd7 100644
>> --- a/drivers/i2c/busses/i2c-tegra.c
>> +++ b/drivers/i2c/busses/i2c-tegra.c
>> @@ -73,6 +73,7 @@
>>  #define I2C_ERR_NO_ACK				BIT(0)
>>  #define I2C_ERR_ARBITRATION_LOST		BIT(1)
>>  #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
>> +#define I2C_ERR_UNEXPECTED_STATUS		BIT(3)
>>  
>>  #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
>>  #define PACKET_HEADER0_PACKET_ID_SHIFT		16
>> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>  	 * prevent overwriting past the end of buf
>>  	 */
>>  	if (rx_fifo_avail > 0 && buf_remaining > 0) {
>> -		BUG_ON(buf_remaining > 3);
>>  		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>>  		val = cpu_to_le32(val);
>>  		memcpy(buf, &val, buf_remaining);
>> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>  		rx_fifo_avail--;
>>  	}
>>  
>> -	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>>  	i2c_dev->msg_buf_remaining = buf_remaining;
>>  	i2c_dev->msg_buf = buf;
>>  
>> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
>>  	 * boundary and fault.
>>  	 */
>>  	if (tx_fifo_avail > 0 && buf_remaining > 0) {
>> -		BUG_ON(buf_remaining > 3);
>>  		memcpy(&val, buf, buf_remaining);
>>  		val = le32_to_cpu(val);
>>  
>> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>  
>>  	if (!i2c_dev->is_curr_dma_xfer) {
>>  		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
>> -			if (i2c_dev->msg_buf_remaining)
>> +			if (i2c_dev->msg_buf_remaining) {
>>  				tegra_i2c_empty_rx_fifo(i2c_dev);
>> -			else
>> -				BUG();
>> +			} else {
>> +				dev_err(i2c_dev->dev, "unexpected rx data request\n");
>> +				i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>> +				goto err;
>> +			}
>>  		}
>>  
>>  		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>> @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>  	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>>  		if (i2c_dev->is_curr_dma_xfer)
>>  			i2c_dev->msg_buf_remaining = 0;
>> -		BUG_ON(i2c_dev->msg_buf_remaining);
>> +		WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>>  		complete(&i2c_dev->msg_complete);
>>  	}
>>  	goto done;
>>
> 
> Very nice, thank you very much! BTW, I think it may worth to add another
> patch that will reset hardware state in a case of the warning since we
> know that something gone wrong.
> 
> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
> 

Something like that:

 	complete(&i2c_dev->msg_complete);

	if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
		goto err;

Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Dmitry Osipenko]

07.06.2019 15:12, Dmitry Osipenko пишет:
> 07.06.2019 15:08, Dmitry Osipenko пишет:
>> 07.06.2019 14:55, Bitan Biswas пишет:
>>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>>> as needed. Replace BUG() with error handling code.
>>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>>
>>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>>> ---
>>>  drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>>>  1 file changed, 8 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>>> index 4dfb4c1..c407bd7 100644
>>> --- a/drivers/i2c/busses/i2c-tegra.c
>>> +++ b/drivers/i2c/busses/i2c-tegra.c
>>> @@ -73,6 +73,7 @@
>>>  #define I2C_ERR_NO_ACK				BIT(0)
>>>  #define I2C_ERR_ARBITRATION_LOST		BIT(1)
>>>  #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
>>> +#define I2C_ERR_UNEXPECTED_STATUS		BIT(3)
>>>  
>>>  #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
>>>  #define PACKET_HEADER0_PACKET_ID_SHIFT		16
>>> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>  	 * prevent overwriting past the end of buf
>>>  	 */
>>>  	if (rx_fifo_avail > 0 && buf_remaining > 0) {
>>> -		BUG_ON(buf_remaining > 3);
>>>  		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>>>  		val = cpu_to_le32(val);
>>>  		memcpy(buf, &val, buf_remaining);
>>> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>  		rx_fifo_avail--;
>>>  	}
>>>  
>>> -	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>>>  	i2c_dev->msg_buf_remaining = buf_remaining;
>>>  	i2c_dev->msg_buf = buf;
>>>  
>>> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>  	 * boundary and fault.
>>>  	 */
>>>  	if (tx_fifo_avail > 0 && buf_remaining > 0) {
>>> -		BUG_ON(buf_remaining > 3);
>>>  		memcpy(&val, buf, buf_remaining);
>>>  		val = le32_to_cpu(val);
>>>  
>>> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>>  
>>>  	if (!i2c_dev->is_curr_dma_xfer) {
>>>  		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
>>> -			if (i2c_dev->msg_buf_remaining)
>>> +			if (i2c_dev->msg_buf_remaining) {
>>>  				tegra_i2c_empty_rx_fifo(i2c_dev);
>>> -			else
>>> -				BUG();
>>> +			} else {
>>> +				dev_err(i2c_dev->dev, "unexpected rx data request\n");
>>> +				i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>>> +				goto err;
>>> +			}
>>>  		}
>>>  
>>>  		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>>> @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>>  	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>>>  		if (i2c_dev->is_curr_dma_xfer)
>>>  			i2c_dev->msg_buf_remaining = 0;
>>> -		BUG_ON(i2c_dev->msg_buf_remaining);
>>> +		WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>>>  		complete(&i2c_dev->msg_complete);
>>>  	}
>>>  	goto done;
>>>
>>
>> Very nice, thank you very much! BTW, I think it may worth to add another
>> patch that will reset hardware state in a case of the warning since we
>> know that something gone wrong.
>>
>> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
>>
> 
> Something like that:
> 
>  	complete(&i2c_dev->msg_complete);
> 
> 	if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
> 		goto err;
> 

Ah, that's inside the ISR, so maybe will make sense to just not complete
the transfer and let it timeout:

	if (!WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
		complete(&i2c_dev->msg_complete);

Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Bitan Biswas]

On 6/7/19 5:18 AM, Dmitry Osipenko wrote:
> 07.06.2019 15:12, Dmitry Osipenko пишет:
>> 07.06.2019 15:08, Dmitry Osipenko пишет:
>>> 07.06.2019 14:55, Bitan Biswas пишет:
>>>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>>>> as needed. Replace BUG() with error handling code.
>>>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>>>
>>>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>>>> ---
>>>>   drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>>>>   1 file changed, 8 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>>>> index 4dfb4c1..c407bd7 100644
>>>> --- a/drivers/i2c/busses/i2c-tegra.c
>>>> +++ b/drivers/i2c/busses/i2c-tegra.c
>>>> @@ -73,6 +73,7 @@
>>>>   #define I2C_ERR_NO_ACK				BIT(0)
>>>>   #define I2C_ERR_ARBITRATION_LOST		BIT(1)
>>>>   #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
>>>> +#define I2C_ERR_UNEXPECTED_STATUS		BIT(3)
>>>>   
>>>>   #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
>>>>   #define PACKET_HEADER0_PACKET_ID_SHIFT		16
>>>> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>>   	 * prevent overwriting past the end of buf
>>>>   	 */
>>>>   	if (rx_fifo_avail > 0 && buf_remaining > 0) {
>>>> -		BUG_ON(buf_remaining > 3);
>>>>   		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>>>>   		val = cpu_to_le32(val);
>>>>   		memcpy(buf, &val, buf_remaining);
>>>> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>>   		rx_fifo_avail--;
>>>>   	}
>>>>   
>>>> -	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>>>>   	i2c_dev->msg_buf_remaining = buf_remaining;
>>>>   	i2c_dev->msg_buf = buf;
>>>>   
>>>> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
>>>>   	 * boundary and fault.
>>>>   	 */
>>>>   	if (tx_fifo_avail > 0 && buf_remaining > 0) {
>>>> -		BUG_ON(buf_remaining > 3);
>>>>   		memcpy(&val, buf, buf_remaining);
>>>>   		val = le32_to_cpu(val);
>>>>   
>>>> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>>>   
>>>>   	if (!i2c_dev->is_curr_dma_xfer) {
>>>>   		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
>>>> -			if (i2c_dev->msg_buf_remaining)
>>>> +			if (i2c_dev->msg_buf_remaining) {
>>>>   				tegra_i2c_empty_rx_fifo(i2c_dev);
>>>> -			else
>>>> -				BUG();
>>>> +			} else {
>>>> +				dev_err(i2c_dev->dev, "unexpected rx data request\n");
>>>> +				i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>>>> +				goto err;
>>>> +			}
>>>>   		}
>>>>   
>>>>   		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>>>> @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>>>   	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>>>>   		if (i2c_dev->is_curr_dma_xfer)
>>>>   			i2c_dev->msg_buf_remaining = 0;
>>>> -		BUG_ON(i2c_dev->msg_buf_remaining);
>>>> +		WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>>>>   		complete(&i2c_dev->msg_complete);
>>>>   	}
>>>>   	goto done;
>>>>
>>>
>>> Very nice, thank you very much! BTW, I think it may worth to add another
>>> patch that will reset hardware state in a case of the warning since we
>>> know that something gone wrong.
>>>
>>> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
>>>
>>
>> Something like that:
>>
>>   	complete(&i2c_dev->msg_complete);
>>
>> 	if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
>> 		goto err;
>>
> 
> Ah, that's inside the ISR, so maybe will make sense to just not complete
> the transfer and let it timeout:
> 
> 	if (!WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
> 		complete(&i2c_dev->msg_complete);
OK. I shall send the updated patch.

-Thanks,
  Bitan

Re: [PATCH V1 6/6] i2c: tegra: remove BUG, BUG_ON

[Bitan Biswas]

On 6/7/19 11:55 AM, Bitan Biswas wrote:
> 
> 
> On 6/7/19 5:18 AM, Dmitry Osipenko wrote:
>> 07.06.2019 15:12, Dmitry Osipenko пишет:
>>> 07.06.2019 15:08, Dmitry Osipenko пишет:
>>>> 07.06.2019 14:55, Bitan Biswas пишет:
>>>>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>>>>> as needed. Replace BUG() with error handling code.
>>>>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>>>>
>>>>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>>>>> ---
>>>>>   drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>>>>>   1 file changed, 8 insertions(+), 7 deletions(-)
>>>>>
>>>>> diff --git a/drivers/i2c/busses/i2c-tegra.c 
>>>>> b/drivers/i2c/busses/i2c-tegra.c
>>>>> index 4dfb4c1..c407bd7 100644
>>>>> --- a/drivers/i2c/busses/i2c-tegra.c
>>>>> +++ b/drivers/i2c/busses/i2c-tegra.c
>>>>> @@ -73,6 +73,7 @@
>>>>>   #define I2C_ERR_NO_ACK                BIT(0)
>>>>>   #define I2C_ERR_ARBITRATION_LOST        BIT(1)
>>>>>   #define I2C_ERR_UNKNOWN_INTERRUPT        BIT(2)
>>>>> +#define I2C_ERR_UNEXPECTED_STATUS        BIT(3)
>>>>>   #define PACKET_HEADER0_HEADER_SIZE_SHIFT    28
>>>>>   #define PACKET_HEADER0_PACKET_ID_SHIFT        16
>>>>> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct 
>>>>> tegra_i2c_dev *i2c_dev)
>>>>>        * prevent overwriting past the end of buf
>>>>>        */
>>>>>       if (rx_fifo_avail > 0 && buf_remaining > 0) {
>>>>> -        BUG_ON(buf_remaining > 3);
>>>>>           val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>>>>>           val = cpu_to_le32(val);
>>>>>           memcpy(buf, &val, buf_remaining);
>>>>> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct 
>>>>> tegra_i2c_dev *i2c_dev)
>>>>>           rx_fifo_avail--;
>>>>>       }
>>>>> -    BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>>>>>       i2c_dev->msg_buf_remaining = buf_remaining;
>>>>>       i2c_dev->msg_buf = buf;
>>>>> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct 
>>>>> tegra_i2c_dev *i2c_dev)
>>>>>        * boundary and fault.
>>>>>        */
>>>>>       if (tx_fifo_avail > 0 && buf_remaining > 0) {
>>>>> -        BUG_ON(buf_remaining > 3);
>>>>>           memcpy(&val, buf, buf_remaining);
>>>>>           val = le32_to_cpu(val);
>>>>> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, 
>>>>> void *dev_id)
>>>>>       if (!i2c_dev->is_curr_dma_xfer) {
>>>>>           if (i2c_dev->msg_read && (status & 
>>>>> I2C_INT_RX_FIFO_DATA_REQ)) {
>>>>> -            if (i2c_dev->msg_buf_remaining)
>>>>> +            if (i2c_dev->msg_buf_remaining) {
>>>>>                   tegra_i2c_empty_rx_fifo(i2c_dev);
>>>>> -            else
>>>>> -                BUG();
>>>>> +            } else {
>>>>> +                dev_err(i2c_dev->dev, "unexpected rx data 
>>>>> request\n");
>>>>> +                i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>>>>> +                goto err;
>>>>> +            }
>>>>>           }
>>>>>           if (!i2c_dev->msg_read && (status & 
>>>>> I2C_INT_TX_FIFO_DATA_REQ)) {
>>>>> @@ -876,7 +877,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void 
>>>>> *dev_id)
>>>>>       if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>>>>>           if (i2c_dev->is_curr_dma_xfer)
>>>>>               i2c_dev->msg_buf_remaining = 0;
>>>>> -        BUG_ON(i2c_dev->msg_buf_remaining);
>>>>> +        WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>>>>>           complete(&i2c_dev->msg_complete);
>>>>>       }
>>>>>       goto done;
>>>>>
>>>>
>>>> Very nice, thank you very much! BTW, I think it may worth to add 
>>>> another
>>>> patch that will reset hardware state in a case of the warning since we
>>>> know that something gone wrong.
>>>>
>>>> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
>>>>
>>>
>>> Something like that:
>>>
>>>       complete(&i2c_dev->msg_complete);
>>>
>>>     if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
>>>         goto err;
>>>
>>
>> Ah, that's inside the ISR, so maybe will make sense to just not complete
>> the transfer and let it timeout:
>>
>>     if (!WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
>>         complete(&i2c_dev->msg_complete);
> OK. I shall send the updated patch.
I see that there is already err label in the ISR that could be jumped 
into. Hence, planning to share updated patch with the error handling.

-regards,
  Bitan