Re: [PATCH] misc/serio_raw: Avoid circular locking.

From: Dmitry Torokhov
Date: Thu Oct 06 2011 - 01:07:36 EST


Hi Thomas,

On Wed, Oct 05, 2011 at 01:02:49PM -0400, Thomas Tuttle wrote:
>
> This patch rearranges serio_raw_connect so that it takes the mutex once
> to allocate a device number and open the serio device, drops it to call
> misc_register, then takes it again to add the serio_raw device to the
> list.
>
> BUG=chromium-os:21113
> TEST=Adhoc: PROVE_LOCKING no longer finds circular locking dependency
>
> Change-Id: I414c5a3d606c28c81e42dcf989e5c55918eb4ea3
> Signed-off-by: Thomas Tuttle <ttuttle@xxxxxxxxxxxx>
> ---
> I think this works, but I'm not familiar enough with the misc and serio
> subsystems to know if this is completely correct, nor if it is the best
> way to break the circular dependency. Feedback would be appreciated.

Thank you for your report; I looked at the driver and (to my
embarrassment) is is quite broken and requires a bit more extensive
fixing. I'll be posting a few patches shortly and would appreciate if
you could look them over and/or test.

Thanks.

--
Dmitry
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