2019-01-30 09:43:10

by [email protected]

Subject: [PATCH] i2c: cadence: try reset when master receive error interrupts

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 <[email protected]>
---
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;

/* 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

2019-02-15 16:10:11

by Shubhrajyoti Datta

Subject: Re: [PATCH] i2c: cadence: try reset when master receive error interrupts

Hi Sxauwsk,

On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <[email protected]> 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 <[email protected]>
> ---
> 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
>
>

2019-02-18 06:36:29

by Shubhrajyoti Datta

Subject: Re: [PATCH] i2c: cadence: try reset when master receive error interrupts

Hi ,
On Sat, Feb 16, 2019 at 1:21 PM [email protected] <[email protected]> wrote:
>
> >Hi Sxauwsk,
> >
> >On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <[email protected]> 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 <[email protected]>
> >> ---
> >> 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.

2019-02-18 08:09:11

by Shubhrajyoti Datta

Subject: Re: Re: [PATCH] i2c: cadence: try reset when master receive error interrupts

On Mon, Feb 18, 2019 at 12:48 PM [email protected] <[email protected]> wrote:
>
> Hi , Shubhrajyoti
>
> >Hi ,
> >On Sat, Feb 16, 2019 at 1:21 PM [email protected] <[email protected]> wrote:
> >>
> >> >Hi Sxauwsk,
> >> >
> >> >On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <[email protected]> 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 <[email protected]>
> >> >> ---
> >> >> 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.
>
>
>
>