Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
as needed. Remove BUG() and mask Rx interrupt similar as Tx
for message fully sent case. Add WARN_ON_ONCE check
for non-zero rx_fifo_avail in tegra_i2c_empty_rx_fifo()
after all processing. Error handling in tegra_i2c_empty_rx_fifo
caller is also added.
Signed-off-by: Bitan Biswas <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 46 ++++++++++++++++++++++++++++++++++--------
1 file changed, 38 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 4dfb4c1..26a7c8c 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
@@ -515,15 +516,23 @@ 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);
+ /* buf_remaining > 3 check not needed as rx_fifo_avail == 0
+ * when (words_to_transfer was > rx_fifo_avail) earlier
+ * in this function
+ */
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
val = cpu_to_le32(val);
memcpy(buf, &val, buf_remaining);
buf_remaining = 0;
rx_fifo_avail--;
}
+ if (WARN_ON_ONCE(rx_fifo_avail))
+ return -EINVAL;
- BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
+ /* buf_remaining > 0 at this point can only have rx_fifo_avail == 0
+ * as this corresponds to (words_to_transfer was > rx_fifo_avail)
+ * case earlier in this function
+ */
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;
@@ -581,7 +590,10 @@ 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);
+ /* buf_remaining > 3 check not needed as tx_fifo_avail == 0
+ * when (words_to_transfer was > tx_fifo_avail) earlier
+ * in this function for non-zero words_to_transfer
+ */
memcpy(&val, buf, buf_remaining);
val = le32_to_cpu(val);
@@ -811,6 +823,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
u32 status;
const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
struct tegra_i2c_dev *i2c_dev = dev_id;
+ int err_val;
status = i2c_readl(i2c_dev, I2C_INT_STATUS);
@@ -847,10 +860,21 @@ 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)
- tegra_i2c_empty_rx_fifo(i2c_dev);
- else
- BUG();
+ err_val = tegra_i2c_empty_rx_fifo(i2c_dev);
+ if ((!(i2c_dev->msg_buf_remaining)) &&
+ (!(status & I2C_INT_PACKET_XFER_COMPLETE)) &&
+ err_val) {
+ /*
+ * Overflow error condition: message fully sent,
+ * with no XFER_COMPLETE interrupt but hardware
+ * asks to transfer more.
+ */
+ tegra_i2c_mask_irq(i2c_dev,
+ I2C_INT_RX_FIFO_DATA_REQ);
+ i2c_dev->msg_err |=
+ I2C_ERR_UNEXPECTED_STATUS;
+ goto err;
+ }
}
if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
@@ -876,7 +900,13 @@ 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);
+ /* Underflow error condition: XFER_COMPLETE before message
+ * fully sent.
+ */
+ if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
+ i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
+ goto err;
+ }
complete(&i2c_dev->msg_complete);
}
goto done;
--
2.7.4
14.06.2019 18:50, Bitan Biswas пишет:
> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
> as needed. Remove BUG() and mask Rx interrupt similar as Tx
> for message fully sent case. Add WARN_ON_ONCE check
> for non-zero rx_fifo_avail in tegra_i2c_empty_rx_fifo()
> after all processing. Error handling in tegra_i2c_empty_rx_fifo
> caller is also added.
>
> Signed-off-by: Bitan Biswas <[email protected]>
> ---
> drivers/i2c/busses/i2c-tegra.c | 46 ++++++++++++++++++++++++++++++++++--------
> 1 file changed, 38 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 4dfb4c1..26a7c8c 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)
What about I2C_ERR_RX_BUFFER_OVERFLOW?
> #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
> #define PACKET_HEADER0_PACKET_ID_SHIFT 16
> @@ -515,15 +516,23 @@ 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);
> + /* buf_remaining > 3 check not needed as rx_fifo_avail == 0
> + * when (words_to_transfer was > rx_fifo_avail) earlier
> + * in this function
> + */
Please start all multiline comments with an empty "/*", it should be the correct
style. There are some places in the kernel where style like yours is used, but I
assume they are not very correct. Besides, yours variant is not consistent with the
style of the rest of comments in this source file. And put a dot in the end for
completeness. Same for the other comments in this patch.
> val = i2c_readl(i2c_dev, I2C_RX_FIFO);
> val = cpu_to_le32(val);
> memcpy(buf, &val, buf_remaining);
> buf_remaining = 0;
> rx_fifo_avail--;
> }
Please add a newline here. All logical parts of the code should be separated to ease
reading and following.
> + if (WARN_ON_ONCE(rx_fifo_avail))
> + return -EINVAL;
>
> - BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
> + /* buf_remaining > 0 at this point can only have rx_fifo_avail == 0
> + * as this corresponds to (words_to_transfer was > rx_fifo_avail)
> + * case earlier in this function
> + */
> i2c_dev->msg_buf_remaining = buf_remaining;
> i2c_dev->msg_buf = buf;
>
> @@ -581,7 +590,10 @@ 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);
> + /* buf_remaining > 3 check not needed as tx_fifo_avail == 0
> + * when (words_to_transfer was > tx_fifo_avail) earlier
> + * in this function for non-zero words_to_transfer
> + */
> memcpy(&val, buf, buf_remaining);
> val = le32_to_cpu(val);
>
> @@ -811,6 +823,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
> u32 status;
> const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
> struct tegra_i2c_dev *i2c_dev = dev_id;
> + int err_val;
>
> status = i2c_readl(i2c_dev, I2C_INT_STATUS);
>
> @@ -847,10 +860,21 @@ 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)
> - tegra_i2c_empty_rx_fifo(i2c_dev);
> - else
> - BUG();
> + err_val = tegra_i2c_empty_rx_fifo(i2c_dev);
> + if ((!(i2c_dev->msg_buf_remaining)) &&
Let's move this check into tegra_i2c_empty_rx_fifo() and return -EINVAL for that case.
This will make code to look cleaner.
> + (!(status & I2C_INT_PACKET_XFER_COMPLETE)) &&
It shouldn't matter that XFER_COMPLETE is set if RX FIFO isn't fully emptied because
it always shall be emptied. Hence this check is not needed and we should error out
regardless.
> + err_val) {
> + /*
> + * Overflow error condition: message fully sent,
> + * with no XFER_COMPLETE interrupt but hardware
> + * asks to transfer more.
> + */
> + tegra_i2c_mask_irq(i2c_dev,
> + I2C_INT_RX_FIFO_DATA_REQ);
No need to mask RX_FIFO_DATA_REQ here because all interrupts are masked on "goto
err:", hence just remove the tegra_i2c_mask_irq().
> + i2c_dev->msg_err |=
> + I2C_ERR_UNEXPECTED_STATUS;
No need to split this into two lines because it's less than 80 chars, write this in a
single line.
> + goto err;
> + }
> }
>
> if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
> @@ -876,7 +900,13 @@ 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);
> + /* Underflow error condition: XFER_COMPLETE before message
> + * fully sent.
> + */
> + if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
> + i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
> + goto err;
> + }
> complete(&i2c_dev->msg_complete);
> }
> goto done;
>
Please address comments in the next revision.
On 6/14/19 10:51 AM, Dmitry Osipenko wrote:
> 14.06.2019 18:50, Bitan Biswas пишет:
>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>> as needed. Remove BUG() and mask Rx interrupt similar as Tx
>> for message fully sent case. Add WARN_ON_ONCE check
>> for non-zero rx_fifo_avail in tegra_i2c_empty_rx_fifo()
>> after all processing. Error handling in tegra_i2c_empty_rx_fifo
>> caller is also added.
>>
>> Signed-off-by: Bitan Biswas <[email protected]>
>> ---
>> drivers/i2c/busses/i2c-tegra.c | 46 ++++++++++++++++++++++++++++++++++--------
>> 1 file changed, 38 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index 4dfb4c1..26a7c8c 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)
>
> What about I2C_ERR_RX_BUFFER_OVERFLOW?
OK.
>
>> #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
>> #define PACKET_HEADER0_PACKET_ID_SHIFT 16
>> @@ -515,15 +516,23 @@ 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);
>> + /* buf_remaining > 3 check not needed as rx_fifo_avail == 0
>> + * when (words_to_transfer was > rx_fifo_avail) earlier
>> + * in this function
>> + */
>
> Please start all multiline comments with an empty "/*", it should be the correct
> style. There are some places in the kernel where style like yours is used, but I
> assume they are not very correct. Besides, yours variant is not consistent with the
> style of the rest of comments in this source file. And put a dot in the end for
> completeness. Same for the other comments in this patch.
>
OK
>> val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>> val = cpu_to_le32(val);
>> memcpy(buf, &val, buf_remaining);
>> buf_remaining = 0;
>> rx_fifo_avail--;
>> }
>
> Please add a newline here. All logical parts of the code should be separated to ease
> reading and following.
OK
>
>> + if (WARN_ON_ONCE(rx_fifo_avail))
>> + return -EINVAL;
>>
>> - BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>> + /* buf_remaining > 0 at this point can only have rx_fifo_avail == 0
>> + * as this corresponds to (words_to_transfer was > rx_fifo_avail)
>> + * case earlier in this function
>> + */
>> i2c_dev->msg_buf_remaining = buf_remaining;
>> i2c_dev->msg_buf = buf;
>>
>> @@ -581,7 +590,10 @@ 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);
>> + /* buf_remaining > 3 check not needed as tx_fifo_avail == 0
>> + * when (words_to_transfer was > tx_fifo_avail) earlier
>> + * in this function for non-zero words_to_transfer
>> + */
>> memcpy(&val, buf, buf_remaining);
>> val = le32_to_cpu(val);
>>
>> @@ -811,6 +823,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>> u32 status;
>> const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
>> struct tegra_i2c_dev *i2c_dev = dev_id;
>> + int err_val;
>>
>> status = i2c_readl(i2c_dev, I2C_INT_STATUS);
>>
>> @@ -847,10 +860,21 @@ 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)
>> - tegra_i2c_empty_rx_fifo(i2c_dev);
>> - else
>> - BUG();
>> + err_val = tegra_i2c_empty_rx_fifo(i2c_dev);
>> + if ((!(i2c_dev->msg_buf_remaining)) &&
>
> Let's move this check into tegra_i2c_empty_rx_fifo() and return -EINVAL for that case.
> This will make code to look cleaner.
OK.
>
>> + (!(status & I2C_INT_PACKET_XFER_COMPLETE)) &&
>
> It shouldn't matter that XFER_COMPLETE is set if RX FIFO isn't fully emptied because
> it always shall be emptied. Hence this check is not needed and we should error out
> regardless.
OK
>
>> + err_val) {
>> + /*
>> + * Overflow error condition: message fully sent,
>> + * with no XFER_COMPLETE interrupt but hardware
>> + * asks to transfer more.
>> + */
>> + tegra_i2c_mask_irq(i2c_dev,
>> + I2C_INT_RX_FIFO_DATA_REQ);
>
> No need to mask RX_FIFO_DATA_REQ here because all interrupts are masked on "goto
> err:", hence just remove the tegra_i2c_mask_irq().
>
>> + i2c_dev->msg_err |=
>> + I2C_ERR_UNEXPECTED_STATUS;
>
> No need to split this into two lines because it's less than 80 chars, write this in a
> single line.
OK
>
>> + goto err;
>> + }
>> }
>>
>> if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>> @@ -876,7 +900,13 @@ 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);
>> + /* Underflow error condition: XFER_COMPLETE before message
>> + * fully sent.
>> + */
>> + if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
>> + i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
>> + goto err;
>> + }
>> complete(&i2c_dev->msg_complete);
>> }
>> goto done;
>>
>
> Please address comments in the next revision.
>
Sorry for the delayed reply. I shared Patch V7 with above changes
earlier today.
-regards,
Bitan
17.06.2019 22:08, Bitan Biswas пишет:
>
>
> On 6/14/19 10:51 AM, Dmitry Osipenko wrote:
>> 14.06.2019 18:50, Bitan Biswas пишет:
>>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>>> as needed. Remove BUG() and mask Rx interrupt similar as Tx
>>> for message fully sent case. Add WARN_ON_ONCE check
>>> for non-zero rx_fifo_avail in tegra_i2c_empty_rx_fifo()
>>> after all processing. Error handling in tegra_i2c_empty_rx_fifo
>>> caller is also added.
>>>
>>> Signed-off-by: Bitan Biswas <[email protected]>
>>> ---
>>> drivers/i2c/busses/i2c-tegra.c | 46 ++++++++++++++++++++++++++++++++++--------
>>> 1 file changed, 38 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>>> index 4dfb4c1..26a7c8c 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)
>>
>> What about I2C_ERR_RX_BUFFER_OVERFLOW?
> OK.
>
>>
>>> #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
>>> #define PACKET_HEADER0_PACKET_ID_SHIFT 16
>>> @@ -515,15 +516,23 @@ 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);
>>> + /* buf_remaining > 3 check not needed as rx_fifo_avail == 0
>>> + * when (words_to_transfer was > rx_fifo_avail) earlier
>>> + * in this function
>>> + */
>>
>> Please start all multiline comments with an empty "/*", it should be the correct
>> style. There are some places in the kernel where style like yours is used, but I
>> assume they are not very correct. Besides, yours variant is not consistent with the
>> style of the rest of comments in this source file. And put a dot in the end for
>> completeness. Same for the other comments in this patch.
>>
> OK
>
>>> val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>>> val = cpu_to_le32(val);
>>> memcpy(buf, &val, buf_remaining);
>>> buf_remaining = 0;
>>> rx_fifo_avail--;
>>> }
>>
>> Please add a newline here. All logical parts of the code should be separated to ease
>> reading and following.
> OK
>
>>
>>> + if (WARN_ON_ONCE(rx_fifo_avail))
>>> + return -EINVAL;
>>> - BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>>> + /* buf_remaining > 0 at this point can only have rx_fifo_avail == 0
>>> + * as this corresponds to (words_to_transfer was > rx_fifo_avail)
>>> + * case earlier in this function
>>> + */
>>> i2c_dev->msg_buf_remaining = buf_remaining;
>>> i2c_dev->msg_buf = buf;
>>> @@ -581,7 +590,10 @@ 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);
>>> + /* buf_remaining > 3 check not needed as tx_fifo_avail == 0
>>> + * when (words_to_transfer was > tx_fifo_avail) earlier
>>> + * in this function for non-zero words_to_transfer
>>> + */
>>> memcpy(&val, buf, buf_remaining);
>>> val = le32_to_cpu(val);
>>> @@ -811,6 +823,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>> u32 status;
>>> const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
>>> struct tegra_i2c_dev *i2c_dev = dev_id;
>>> + int err_val;
>>> status = i2c_readl(i2c_dev, I2C_INT_STATUS);
>>> @@ -847,10 +860,21 @@ 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)
>>> - tegra_i2c_empty_rx_fifo(i2c_dev);
>>> - else
>>> - BUG();
>>> + err_val = tegra_i2c_empty_rx_fifo(i2c_dev);
>>> + if ((!(i2c_dev->msg_buf_remaining)) &&
>>
>> Let's move this check into tegra_i2c_empty_rx_fifo() and return -EINVAL for that case.
>> This will make code to look cleaner.
> OK.
>
>
>>
>>> + (!(status & I2C_INT_PACKET_XFER_COMPLETE)) &&
>>
>> It shouldn't matter that XFER_COMPLETE is set if RX FIFO isn't fully emptied because
>> it always shall be emptied. Hence this check is not needed and we should error out
>> regardless.
> OK
>
>>
>>> + err_val) {
>>> + /*
>>> + * Overflow error condition: message fully sent,
>>> + * with no XFER_COMPLETE interrupt but hardware
>>> + * asks to transfer more.
>>> + */
>>> + tegra_i2c_mask_irq(i2c_dev,
>>> + I2C_INT_RX_FIFO_DATA_REQ);
>>
>> No need to mask RX_FIFO_DATA_REQ here because all interrupts are masked on "goto
>> err:", hence just remove the tegra_i2c_mask_irq().
>>
>>> + i2c_dev->msg_err |=
>>> + I2C_ERR_UNEXPECTED_STATUS;
>>
>> No need to split this into two lines because it's less than 80 chars, write this in a
>> single line.
> OK
>
>>
>>> + goto err;
>>> + }
>>> }
>>> if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>>> @@ -876,7 +900,13 @@ 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);
>>> + /* Underflow error condition: XFER_COMPLETE before message
>>> + * fully sent.
>>> + */
>>> + if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
>>> + i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
>>> + goto err;
>>> + }
>>> complete(&i2c_dev->msg_complete);
>>> }
>>> goto done;
>>>
>>
>> Please address comments in the next revision.
>>
>
> Sorry for the delayed reply. I shared Patch V7 with above changes earlier today.
No problems, please take your time. The V7 is almost good, looking forward to v8!