From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755632Ab2C0TSS (ORCPT ); Tue, 27 Mar 2012 15:18:18 -0400 Received: from smtp.fireflyinternet.com ([109.228.6.236]:64400 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755278Ab2C0TSQ (ORCPT ); Tue, 27 Mar 2012 15:18:16 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.66.37; From: Chris Wilson Subject: Re: [PATCH 10/13 v4] drm/i915/intel_i2c: always wait for IDLE before clearing NAK To: Daniel Kurtz , Daniel Vetter , Keith Packard , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Benson Leung , Yufeng Shen , Daniel Kurtz In-Reply-To: <1332873382-29373-11-git-send-email-djkurtz@chromium.org> References: <1332873382-29373-1-git-send-email-djkurtz@chromium.org> <1332873382-29373-11-git-send-email-djkurtz@chromium.org> Date: Tue, 27 Mar 2012 20:17:59 +0100 X-Originating-IP: 78.156.66.37 Message-ID: <1332875892_117312@CP5-2952> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 28 Mar 2012 02:36:19 +0800, Daniel Kurtz wrote: > The GMBUS controller can report a NAK condition while a transaction is > still active. If the driver is fast enough, and the bus is slow enough, > the driver may clear the NAK condition while the controller is still > busy, resulting in a confused GMBUS controller. This will leave the > controller in a bad state such that the next transaction may fail. > > Also, return -ENXIO if a device NAKs a transaction. > > Note: this patch also refactors gmbus_xfer to remove the "done" label. > > Signed-off-by: Daniel Kurtz Thanks for clarifying the appropriate return codes. Reviewed-by: Chris Wilson -Chris -- Chris Wilson, Intel Open Source Technology Centre