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

From: Peter Korsgaard
Date: Thu Apr 13 2023 - 05:58:37 EST


>>>>> "Matthias" == Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> writes:

> 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.

Acked-by: Peter Korsgaard <peter@xxxxxxxxxxxxx>

--
Bye, Peter Korsgaard