Re: [PATCH 5/9] drm/i915/intel_i2c: add locking around i2c algorithmaccesses

From: Daniel Vetter
Date: Sun Mar 18 2012 - 14:18:57 EST


On Wed, Mar 07, 2012 at 07:50:46PM +0800, Daniel Kurtz wrote:
> The i915 has multiple i2c adapters. However, they all share a single
> single set of i2c control registers (algorithm). Thus, different threads
> trying to access different adapters could interfere with each other.
>
> Note: different threads trying to access the same channel is already
> handled in the i2c-core using the i2c adapter lock.
>
> This patch adds a mutex to serialize access to the gmbus_xfer routine.
> Note: the same mutex serializes both bit banged and native xfers.
>
> Signed-off-by: Yufeng Shen <miletus@xxxxxxxxxxxx>
> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>

This is already fixed in

commit 8a8ed1f5143b3df312e436ab15290e4a7ca6a559
Author: Yufeng Shen <miletus@xxxxxxxxxxxx>
Date: Mon Feb 13 17:36:54 2012 -0500

drm/i915: Fix race condition in accessing GMBUS

There are also a few gmbus changes already queued up in my -next tree at

http://cgit.freedesktop.org/~danvet/drm-intel/log/?h=drm-intel-next-queued

Please rebase your patch series on top of that (with Chris' suggestion
incorporated).

Thanks, Daniel
--
Daniel Vetter
Mail: daniel@xxxxxxxx
Mobile: +41 (0)79 365 57 48
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