From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756123Ab2CRSSp (ORCPT ); Sun, 18 Mar 2012 14:18:45 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:42493 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756029Ab2CRSSn (ORCPT ); Sun, 18 Mar 2012 14:18:43 -0400 Date: Sun, 18 Mar 2012 19:19:25 +0100 From: Daniel Vetter To: Daniel Kurtz Cc: Keith Packard , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Yufeng Shen , Benson Leung , Sameer Nanda Subject: Re: [PATCH 5/9] drm/i915/intel_i2c: add locking around i2c algorithm accesses Message-ID: <20120318181925.GG4286@phenom.ffwll.local> Mail-Followup-To: Daniel Kurtz , Keith Packard , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Yufeng Shen , Benson Leung , Sameer Nanda References: <1331121050-17857-1-git-send-email-djkurtz@chromium.org> <1331121050-17857-6-git-send-email-djkurtz@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331121050-17857-6-git-send-email-djkurtz@chromium.org> X-Operating-System: Linux phenom 3.2.0-1-amd64 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Signed-off-by: Daniel Kurtz This is already fixed in commit 8a8ed1f5143b3df312e436ab15290e4a7ca6a559 Author: Yufeng Shen 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@ffwll.ch Mobile: +41 (0)79 365 57 48