diff mbox

[V2,2/2] drivers: i2c: qup: Fix error handling

Message ID 1462534274-28925-3-git-send-email-sricharan@codeaurora.org
State Changes Requested
Headers show

Commit Message

Sricharan Ramabadhran May 6, 2016, 11:31 a.m. UTC
Among the bus errors reported from the QUP_MASTER_STATUS register
only NACK is considered and transfer gets suspended, while
other errors are ignored. Correct this and suspend the transfer
for other errors as well. This avoids unnessecary 'timeouts' which
happens when waiting for events that would never happen when there
is already an error condition on the bus.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
---
 drivers/i2c/busses/i2c-qup.c | 42 +++++++++++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 13 deletions(-)

Comments

Naveen Kaje May 6, 2016, 5:53 p.m. UTC | #1
On 5/6/2016 5:31 AM, Sricharan R wrote:
> Among the bus errors reported from the QUP_MASTER_STATUS register
> only NACK is considered and transfer gets suspended, while
> other errors are ignored. Correct this and suspend the transfer
> for other errors as well. This avoids unnessecary 'timeouts' which
> happens when waiting for events that would never happen when there
> is already an error condition on the bus.
>
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> Reviewed-by: Andy Gross <andy.gross@linaro.org>
Hi Sricharan,
Looks good to me. Tested on QDF2432 platform.

Reviewed-by: Naveen Kaje <nkaje@codeaurora.org>
Tested-by: Naveen Kaje <nkaje@codeaurora.org>

> ---
>   drivers/i2c/busses/i2c-qup.c | 42 +++++++++++++++++++++++++++++-------------
>   1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
> index 8620e99..af52a47 100644
> --- a/drivers/i2c/busses/i2c-qup.c
> +++ b/drivers/i2c/busses/i2c-qup.c
> @@ -310,6 +310,7 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
>   	u32 opflags;
>   	u32 status;
>   	u32 shift = __ffs(op);
> +	int ret = 0;
>   
>   	len *= qup->one_byte_t;
>   	/* timeout after a wait of twice the max time */
> @@ -321,18 +322,31 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
>   
>   		if (((opflags & op) >> shift) == val) {
>   			if ((op == QUP_OUT_NOT_EMPTY) && qup->is_last) {
> -				if (!(status & I2C_STATUS_BUS_ACTIVE))
> -					return 0;
> +				if (!(status & I2C_STATUS_BUS_ACTIVE)) {
> +					ret = 0;
> +					goto done;
> +				}
>   			} else {
> -				return 0;
> +				ret = 0;
> +				goto done;
>   			}
>   		}
>   
> -		if (time_after(jiffies, timeout))
> -			return -ETIMEDOUT;
> -
> +		if (time_after(jiffies, timeout)) {
> +			ret = -ETIMEDOUT;
> +			goto done;
> +		}
>   		usleep_range(len, len * 2);
>   	}
> +
> +done:
> +	if (qup->bus_err || qup->qup_err) {
> +		if (qup->bus_err & QUP_I2C_NACK_FLAG)
> +			dev_err(qup->dev, "NACK from %x\n", qup->msg->addr);
> +		ret = -EIO;
> +	}
> +
> +	return ret;
>   }
>   
>   static void qup_i2c_set_write_mode_v2(struct qup_i2c_dev *qup,
> @@ -796,7 +810,6 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
>   		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
>   			msg--;
>   			dev_err(qup->dev, "NACK from %x\n", msg->addr);
> -			ret = -EIO;
>   
>   			if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
>   				dev_err(qup->dev, "change to run state timed out");
> @@ -818,6 +831,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
>   
>   			qup_i2c_rel_dma(qup);
>   		}
> +		ret = -EIO;
>   	}
>   
>   	dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
> @@ -841,9 +855,6 @@ static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
>   	if (ret)
>   		goto out;
>   
> -	qup->bus_err = 0;
> -	qup->qup_err = 0;
> -
>   	writel(0, qup->base + QUP_MX_INPUT_CNT);
>   	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
>   
> @@ -882,10 +893,9 @@ static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
>   	}
>   
>   	if (qup->bus_err || qup->qup_err) {
> -		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
> +		if (qup->bus_err & QUP_I2C_NACK_FLAG)
>   			dev_err(qup->dev, "NACK from %x\n", msg->addr);
> -			ret = -EIO;
> -		}
> +		ret = -EIO;
>   	}
>   
>   	return ret;
> @@ -1178,6 +1188,9 @@ static int qup_i2c_xfer(struct i2c_adapter *adap,
>   	if (ret < 0)
>   		goto out;
>   
> +	qup->bus_err = 0;
> +	qup->qup_err = 0;
> +
>   	writel(1, qup->base + QUP_SW_RESET);
>   	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
>   	if (ret)
> @@ -1227,6 +1240,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
>   	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
>   	int ret, len, idx = 0, use_dma = 0;
>   
> +	qup->bus_err = 0;
> +	qup->qup_err = 0;
> +
>   	ret = pm_runtime_get_sync(qup->dev);
>   	if (ret < 0)
>   		goto out;

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Wolfram Sang May 13, 2016, 11:48 a.m. UTC | #2
On Fri, May 06, 2016 at 05:01:14PM +0530, Sricharan R wrote:
> Among the bus errors reported from the QUP_MASTER_STATUS register
> only NACK is considered and transfer gets suspended, while
> other errors are ignored. Correct this and suspend the transfer
> for other errors as well. This avoids unnessecary 'timeouts' which
> happens when waiting for events that would never happen when there
> is already an error condition on the bus.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> Reviewed-by: Andy Gross <andy.gross@linaro.org>

Please check Documentation/i2c/fault-codes for proper fault codes.
Wolfram Sang May 13, 2016, 11:50 a.m. UTC | #3
On Fri, May 13, 2016 at 01:48:23PM +0200, Wolfram Sang wrote:
> On Fri, May 06, 2016 at 05:01:14PM +0530, Sricharan R wrote:
> > Among the bus errors reported from the QUP_MASTER_STATUS register
> > only NACK is considered and transfer gets suspended, while
> > other errors are ignored. Correct this and suspend the transfer
> > for other errors as well. This avoids unnessecary 'timeouts' which
> > happens when waiting for events that would never happen when there
> > is already an error condition on the bus.
> > 
> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> > Reviewed-by: Andy Gross <andy.gross@linaro.org>
> 
> Please check Documentation/i2c/fault-codes for proper fault codes.

And while we are here: NACK is not an error but a valid response. Can
you remove the dev_err related to that? Otherwise tools like i2cdetect
will probably flood your log.
Sricharan Ramabadhran May 16, 2016, 5:59 a.m. UTC | #4
Hi,
> > > Among the bus errors reported from the QUP_MASTER_STATUS register
> > > only NACK is considered and transfer gets suspended, while other
> > > errors are ignored. Correct this and suspend the transfer for other
> > > errors as well. This avoids unnessecary 'timeouts' which happens
> > > when waiting for events that would never happen when there is
> > > already an error condition on the bus.
> > >
> > > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> > > Reviewed-by: Andy Gross <andy.gross@linaro.org>
> >
> > Please check Documentation/i2c/fault-codes for proper fault codes.
> 
    Ok, Thanks for pointing this out. So, for NACK I think it is more
appropriate to
    return -ENXIO and -EIO for other errors. Will correct this.

> And while we are here: NACK is not an error but a valid response. Can you
> remove the dev_err related to that? Otherwise tools like i2cdetect will
> probably flood your log.
  Ok, will correct this.

Regards,
 Sricharan         

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diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 8620e99..af52a47 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -310,6 +310,7 @@  static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
 	u32 opflags;
 	u32 status;
 	u32 shift = __ffs(op);
+	int ret = 0;
 
 	len *= qup->one_byte_t;
 	/* timeout after a wait of twice the max time */
@@ -321,18 +322,31 @@  static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
 
 		if (((opflags & op) >> shift) == val) {
 			if ((op == QUP_OUT_NOT_EMPTY) && qup->is_last) {
-				if (!(status & I2C_STATUS_BUS_ACTIVE))
-					return 0;
+				if (!(status & I2C_STATUS_BUS_ACTIVE)) {
+					ret = 0;
+					goto done;
+				}
 			} else {
-				return 0;
+				ret = 0;
+				goto done;
 			}
 		}
 
-		if (time_after(jiffies, timeout))
-			return -ETIMEDOUT;
-
+		if (time_after(jiffies, timeout)) {
+			ret = -ETIMEDOUT;
+			goto done;
+		}
 		usleep_range(len, len * 2);
 	}
+
+done:
+	if (qup->bus_err || qup->qup_err) {
+		if (qup->bus_err & QUP_I2C_NACK_FLAG)
+			dev_err(qup->dev, "NACK from %x\n", qup->msg->addr);
+		ret = -EIO;
+	}
+
+	return ret;
 }
 
 static void qup_i2c_set_write_mode_v2(struct qup_i2c_dev *qup,
@@ -796,7 +810,6 @@  static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
 		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
 			msg--;
 			dev_err(qup->dev, "NACK from %x\n", msg->addr);
-			ret = -EIO;
 
 			if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
 				dev_err(qup->dev, "change to run state timed out");
@@ -818,6 +831,7 @@  static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
 
 			qup_i2c_rel_dma(qup);
 		}
+		ret = -EIO;
 	}
 
 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
@@ -841,9 +855,6 @@  static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
 	if (ret)
 		goto out;
 
-	qup->bus_err = 0;
-	qup->qup_err = 0;
-
 	writel(0, qup->base + QUP_MX_INPUT_CNT);
 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
 
@@ -882,10 +893,9 @@  static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
 	}
 
 	if (qup->bus_err || qup->qup_err) {
-		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
+		if (qup->bus_err & QUP_I2C_NACK_FLAG)
 			dev_err(qup->dev, "NACK from %x\n", msg->addr);
-			ret = -EIO;
-		}
+		ret = -EIO;
 	}
 
 	return ret;
@@ -1178,6 +1188,9 @@  static int qup_i2c_xfer(struct i2c_adapter *adap,
 	if (ret < 0)
 		goto out;
 
+	qup->bus_err = 0;
+	qup->qup_err = 0;
+
 	writel(1, qup->base + QUP_SW_RESET);
 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
 	if (ret)
@@ -1227,6 +1240,9 @@  static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
 	int ret, len, idx = 0, use_dma = 0;
 
+	qup->bus_err = 0;
+	qup->qup_err = 0;
+
 	ret = pm_runtime_get_sync(qup->dev);
 	if (ret < 0)
 		goto out;