From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 09/13 v4] drm/i915/intel_i2c: use double-buffered writes Date: Tue, 27 Mar 2012 19:45:22 +0100 Message-ID: <1332873931_116908@CP5-2952> References: <1332873382-29373-1-git-send-email-djkurtz@chromium.org> <1332873382-29373-10-git-send-email-djkurtz@chromium.org> Return-path: In-Reply-To: <1332873382-29373-10-git-send-email-djkurtz@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Daniel Vetter , Keith Packard , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Benson Leung , Yufeng Shen , Daniel Kurtz List-Id: dri-devel@lists.freedesktop.org On Wed, 28 Mar 2012 02:36:18 +0800, Daniel Kurtz wrote: > @@ -276,6 +269,13 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg, > > I915_WRITE(GMBUS3 + reg_offset, val); > POSTING_READ(GMBUS2 + reg_offset); You might as well squash this posting read as the write flush is redundant given the following read of GMBUS2. > + > + if (wait_for(I915_READ(GMBUS2 + reg_offset) & > + (GMBUS_SATOER | GMBUS_HW_RDY), > + 50)) > + return -ETIMEDOUT; > + if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER) > + return -ENXIO; -- Chris Wilson, Intel Open Source Technology Centre From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756020Ab2C0Spm (ORCPT ); Tue, 27 Mar 2012 14:45:42 -0400 Received: from smtp.fireflyinternet.com ([109.228.6.236]:60185 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755707Ab2C0Spl (ORCPT ); Tue, 27 Mar 2012 14:45:41 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.66.37; From: Chris Wilson Subject: Re: [PATCH 09/13 v4] drm/i915/intel_i2c: use double-buffered writes 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: <1332873382-29373-10-git-send-email-djkurtz@chromium.org> References: <1332873382-29373-1-git-send-email-djkurtz@chromium.org> <1332873382-29373-10-git-send-email-djkurtz@chromium.org> Date: Tue, 27 Mar 2012 19:45:22 +0100 X-Originating-IP: 78.156.66.37 Message-ID: <1332873931_116908@CP5-2952> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 28 Mar 2012 02:36:18 +0800, Daniel Kurtz wrote: > @@ -276,6 +269,13 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg, > > I915_WRITE(GMBUS3 + reg_offset, val); > POSTING_READ(GMBUS2 + reg_offset); You might as well squash this posting read as the write flush is redundant given the following read of GMBUS2. > + > + if (wait_for(I915_READ(GMBUS2 + reg_offset) & > + (GMBUS_SATOER | GMBUS_HW_RDY), > + 50)) > + return -ETIMEDOUT; > + if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER) > + return -ENXIO; -- Chris Wilson, Intel Open Source Technology Centre