i2c: cadence: try reset when master receive error interrupts

Message ID 20190129195214.30272-1-sxauwsk@163.com
State New
Headers show
Series
  • i2c: cadence: try reset when master receive error interrupts
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Commit Message

Shikai Wang Jan. 29, 2019, 7:52 p.m.
When the adapter receive error interrupts, such as NACK, arbitration lost,
cdns_i2c_master_xfer return to the caller directly instead of resuming 
the adapter which resulted in the adapter being out of control.

So when driver detect err_status then try to repair and fix it.

Signed-off-by: sxauwsk <sxauwsk@163.com>
---
 drivers/i2c/busses/i2c-cadence.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Comments

Shubhrajyoti Datta Feb. 15, 2019, 11:07 a.m. | #1
Hi Sxauwsk,

On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <sxauwsk@163.com> wrote:
>
> When the adapter receive error interrupts, such as NACK, arbitration lost,
> cdns_i2c_master_xfer return to the caller directly instead of resuming
> the adapter which resulted in the adapter being out of control.
>
> So when driver detect err_status then try to repair and fix it.
>
> Signed-off-by: sxauwsk <sxauwsk@163.com>
> ---
>  drivers/i2c/busses/i2c-cadence.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> index b13605718291..e10048d7524a 100644
> --- a/drivers/i2c/busses/i2c-cadence.c
> +++ b/drivers/i2c/busses/i2c-cadence.c
> @@ -548,10 +548,6 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
>         cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
>                           CDNS_I2C_IDR_OFFSET);
>
> -       /* If it is bus arbitration error, try again */
> -       if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
> -               return -EAGAIN;
> -
>         return 0;
>  }
>
> @@ -617,13 +613,19 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
>                         id->bus_hold_flag = 0;
>
>                 ret = cdns_i2c_process_msg(id, msgs, adap);
> -               if (ret)
> +               if (!ret)
>                         goto out;
>
In case  the Arbitration error happend  the cdns_i2c_process_msg would return 0
and we will miss the check  below.

Am I missing something ?

>                 /* Report the other error interrupts to application */
>                 if (id->err_status) {
>                         cdns_i2c_master_reset(adap);
>
> +                       /* If it is bus arbitration error, try again */
> +                       if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
> +                               ret = -EAGAIN;
> +                               goto out;
> +                       }
> +
>                         if (id->err_status & CDNS_I2C_IXR_NACK) {
>                                 ret = -ENXIO;
>                                 goto out;
> --
> 2.19.2
>
>
Shubhrajyoti Datta Feb. 18, 2019, 6:33 a.m. | #2
Hi ,
On Sat, Feb 16, 2019 at 1:21 PM sxauwsk@163.com <sxauwsk@163.com> wrote:
>
> >Hi Sxauwsk,
> >
> >On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <sxauwsk@163.com> wrote:
> >>
> >> When the adapter receive error interrupts, such as NACK, arbitration lost,
> >> cdns_i2c_master_xfer return to the caller directly instead of resuming
> >> the adapter which resulted in the adapter being out of control.
> >>
> >> So when driver detect err_status then try to repair and fix it.
> >>
> >> Signed-off-by: sxauwsk <sxauwsk@163.com>
> >> ---
> >>  drivers/i2c/busses/i2c-cadence.c | 12 +++++++-----
> >>  1 file changed, 7 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> >> index b13605718291..e10048d7524a 100644
> >> --- a/drivers/i2c/busses/i2c-cadence.c
> >> +++ b/drivers/i2c/busses/i2c-cadence.c
> >> @@ -548,10 +548,6 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
> >>         cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
> >>                           CDNS_I2C_IDR_OFFSET);
> >>
> >> -       /* If it is bus arbitration error, try again */
> >> -       if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
> >> -               return -EAGAIN;
> >> -
> >>         return 0;
> >>  }
> >>
> >> @@ -617,13 +613,19 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> >>                         id->bus_hold_flag = 0;
> >>
> >>                 ret = cdns_i2c_process_msg(id, msgs, adap);
> >> -               if (ret)
> >> +               if (!ret)
> >>                         goto out;
> >>
> >In case  the Arbitration error happend  the cdns_i2c_process_msg would return 0
> >and we will miss the check  below.
> >
> >Am I missing something ?
> >
> >>                 /* Report the other error interrupts to application */
> >>                 if (id->err_status) {
> >>                         cdns_i2c_master_reset(adap);
> >>
> >> +                       /* If it is bus arbitration error, try again */
> >> +                       if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
> >> +                               ret = -EAGAIN;
> >> +                               goto out;
> >> +                       }
> >> +
> >>                         if (id->err_status & CDNS_I2C_IXR_NACK) {
> >>                                 ret = -ENXIO;
> >>                                 goto out;
> >> --
> >> 2.19.2
> >>
> >>
>
> In cdns_i2c_process_msg process, when detect arbitration lost error return -EAGAIN to  cdns_i2c_master_xfer,  not return 0
> that mean cdns_i2c_process_msg  just go out ignore error check and  problem occur, So we should do something when arbitration error detect.

Arbitration lost is fine how about other errors like NACK.
Shubhrajyoti Datta Feb. 18, 2019, 7:59 a.m. | #3
On Mon, Feb 18, 2019 at 12:48 PM sxauwsk@163.com <sxauwsk@163.com> wrote:
>
> Hi , Shubhrajyoti
>
> >Hi ,
> >On Sat, Feb 16, 2019 at 1:21 PM sxauwsk@163.com <sxauwsk@163.com> wrote:
> >>
> >> >Hi Sxauwsk,
> >> >
> >> >On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <sxauwsk@163.com> wrote:
> >> >>
> >> >> When the adapter receive error interrupts, such as NACK, arbitration lost,
> >> >> cdns_i2c_master_xfer return to the caller directly instead of resuming
> >> >> the adapter which resulted in the adapter being out of control.
> >> >>
> >> >> So when driver detect err_status then try to repair and fix it.
> >> >>
> >> >> Signed-off-by: sxauwsk <sxauwsk@163.com>
> >> >> ---
> >> >>  drivers/i2c/busses/i2c-cadence.c | 12 +++++++-----
> >> >>  1 file changed, 7 insertions(+), 5 deletions(-)
> >> >>
> >> >> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> >> >> index b13605718291..e10048d7524a 100644
> >> >> --- a/drivers/i2c/busses/i2c-cadence.c
> >> >> +++ b/drivers/i2c/busses/i2c-cadence.c
> >> >> @@ -548,10 +548,6 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
> >> >>         cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
> >> >>                           CDNS_I2C_IDR_OFFSET);
> >> >>
> >> >> -       /* If it is bus arbitration error, try again */
> >> >> -       if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
> >> >> -               return -EAGAIN;
> >> >> -
> >> >>         return 0;
> >> >>  }
> >> >>
> >> >> @@ -617,13 +613,19 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> >> >>                         id->bus_hold_flag = 0;
> >> >>
> >> >>                 ret = cdns_i2c_process_msg(id, msgs, adap);
> >> >> -               if (ret)
> >> >> +               if (!ret)
> >> >>                         goto out;
> >> >>
> >> >In case  the Arbitration error happend  the cdns_i2c_process_msg would return 0
> >> >and we will miss the check  below.
> >> >
> >> >Am I missing something ?
> >> >
> >> >>                 /* Report the other error interrupts to application */
> >> >>                 if (id->err_status) {
> >> >>                         cdns_i2c_master_reset(adap);
> >> >>
> >> >> +                       /* If it is bus arbitration error, try again */
> >> >> +                       if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
> >> >> +                               ret = -EAGAIN;
> >> >> +                               goto out;
> >> >> +                       }
> >> >> +
> >> >>                         if (id->err_status & CDNS_I2C_IXR_NACK) {
> >> >>                                 ret = -ENXIO;
> >> >>                                 goto out;
> >> >> --
> >> >> 2.19.2
> >> >>
> >> >>
> >>
> >> In cdns_i2c_process_msg process, when detect arbitration lost error return -EAGAIN to  cdns_i2c_master_xfer,  not return 0
> >> that mean cdns_i2c_process_msg  just go out ignore error check and  problem occur, So we should do something when arbitration error detect.
> >
> >Arbitration lost is fine how about other errors like NACK.
>
> >> >>                 ret = cdns_i2c_process_msg(id, msgs, adap);
> >> >> -               if (ret)
> >> >> +               if (!ret)
> >> >>                         goto out;
>
> Yes, you're right,  This place I should't make any change,  perfect solution!
>
> >> >>
> >> >> -       /* If it is bus arbitration error, try again */
> >> >> -       if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
> >> >> -               return -EAGAIN;
> >> >> -
> >> >>         return 0;
> >> >>  }
>
>
> >> >>                 /* Report the other error interrupts to application */
> >> >>                 if (id->err_status) {
> >> >>                         cdns_i2c_master_reset(adap);
> >> >>
> >> >> +                       /* If it is bus arbitration error, try again */
> >> >> +                       if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
> >> >> +                               ret = -EAGAIN;
> >> >> +                               goto out;
> >> >> +                       }
> >> >> +
>
> Maybe Just remove Arbitration lost Detect part from  cdns_i2c_process_msg function,  then add to cdns_i2c_master_xfer,  Do you think?

I agree.
>
>
>
>

Patch

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b13605718291..e10048d7524a 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -548,10 +548,6 @@  static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
 	cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
 			  CDNS_I2C_IDR_OFFSET);
 
-	/* If it is bus arbitration error, try again */
-	if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
-		return -EAGAIN;
-
 	return 0;
 }
 
@@ -617,13 +613,19 @@  static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			id->bus_hold_flag = 0;
 
 		ret = cdns_i2c_process_msg(id, msgs, adap);
-		if (ret)
+		if (!ret)
 			goto out;
 
 		/* Report the other error interrupts to application */
 		if (id->err_status) {
 			cdns_i2c_master_reset(adap);
 
+			/* If it is bus arbitration error, try again */
+			if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
+				ret = -EAGAIN;
+				goto out;
+			}
+
 			if (id->err_status & CDNS_I2C_IXR_NACK) {
 				ret = -ENXIO;
 				goto out;