Re: [PATCH v2] i2c: ocores: generate stop condition after timeout in polling mode

[Federico Vaga]

On Thu, Apr 13, 2023 at 11:37:37AM +0200, Matthias Schiffer wrote:
> From: Gregor Herburger <gregor.herburger@xxxxxxxxxxxx>
>
> In polling mode, no stop condition is generated after a timeout. This
> causes SCL to remain low and thereby block the bus. If this happens
> during a transfer it can cause slaves to misinterpret the subsequent
> transfer and return wrong values.
>
> To solve this, pass the ETIMEDOUT error up from ocores_process_polling()
> instead of setting STATE_ERROR directly. The caller is adjusted to call
> ocores_process_timeout() on error both in polling and in IRQ mode, which
> will set STATE_ERROR and generate a stop condition.
>
> Fixes: 69c8c0c0efa8 ("i2c: ocores: add polling interface")
> Signed-off-by: Gregor Herburger <gregor.herburger@xxxxxxxxxxxx>
> Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> ---
>
> v2: style improvements based on feedback from Federico and Andrew. I went
>    with a slightly different solution than Andrew suggested to avoid using
>    the ret variable for two different kinds of returns.
>
> drivers/i2c/busses/i2c-ocores.c | 35 ++++++++++++++++++---------------
> 1 file changed, 19 insertions(+), 16 deletions(-)

Reviewed-by: Federico Vaga <federico.vaga@xxxxxxx>

--
Federico Vaga - CERN BE-CEM-EDL