Hi ,
On Sat, Feb 16, 2019 at 1:21 PM sxau...@163.com <sxau...@163.com> wrote:
>
> >Hi Sxauwsk,
> >
> >On Wed, Jan 30, 2019 at 3:13 PM sxauwsk <sxau...@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 <sxau...@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.
