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

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