Re: [1/4] gpio: gpio-f7188x: Use mutex for access serialisation.

From: Vincent Pelletier
Date: Sat Sep 12 2015 - 09:26:51 EST


Hello Simon,

On Thu, 10 Sep 2015 00:01:40 +0200, Simon Guinot
<simon.guinot@xxxxxxxxxxxx> wrote:
> Vincent (Donnefort) finally succeeds to reproduce the issue. The setup
> is quite simple. You only have to flood the gpio-f7188x driver via the
> sysfs GPIO interface. Nothing more is needed.
>
> After some debugging we discovered that the problem comes from the
> __request_region function which don't handle very well concurrent
> requests on a muxed region.
>
> I will send a patch as a reply to this email. Please, can you test it ?

I reverted my mutex-adding commit, applied given patch, and could not
reproduce the error after a few minutes with my test-case, so I think
this solves the issue.

Tested-by: Vincent Pelletier <plr.vincent@xxxxxxxxx>


I rebased my others gpio patches, unrelated to this issue:

gpio: gpio-f7188x: Implement get_direction.
gpio: gpio-f7188x: "get" should retrieve sensed level when available.
gpio: gpio-f7188x: GPIO bank 0 bit 0 is not available on f71869a

Should I resend ?
I have not checked other model's datasheets, FWIW.

Regards,
--
Vincent Pelletier
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/