From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:32818 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348AbcHRL6V (ORCPT ); Thu, 18 Aug 2016 07:58:21 -0400 Subject: Patch "drm: aux ->transfer() can return 0, deal with it" has been added to the 4.7-stable tree To: ville.syrjala@linux.intel.com, airlied@redhat.com, cpaul@redhat.com, daniel.vetter@ffwll.ch, gregkh@linuxfoundation.org Cc: , From: Date: Thu, 18 Aug 2016 13:57:03 +0200 Message-ID: <14715214231333@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled drm: aux ->transfer() can return 0, deal with it to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-aux-transfer-can-return-0-deal-with-it.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From a1f5524a66ff6284d1380cdd7723de82698ff9d3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 28 Jul 2016 17:54:42 +0300 Subject: drm: aux ->transfer() can return 0, deal with it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ville Syrjälä commit a1f5524a66ff6284d1380cdd7723de82698ff9d3 upstream. Restore the correct behaviour (as in check msg.reply) when aux ->transfer() returns 0. It got removed in commit 82922da39190 ("drm/dp_helper: Retry aux transactions on all errors") Now I can actually dump the "entire" DPCD on a Dell UP2314Q with ddrescue. It has some offsets in the DPCD that can't be read for some resaon, all you get is defers. Previously ddrescue would just give up at the first unredable offset on account of read() returning 0 means EOF. Here's the ddrescue log for the interested: 0x00000000 0x00001400 + 0x00001400 0x00000030 - 0x00001430 0x000001D0 + 0x00001600 0x00000030 - 0x00001630 0x0001F9D0 + 0x00021000 0x00000001 - 0x00021001 0x000DEFFF + Cc: Lyude Cc: Daniel Vetter Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -203,7 +203,7 @@ static int drm_dp_dpcd_access(struct drm ret = aux->transfer(aux, &msg); - if (ret > 0) { + if (ret >= 0) { native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { if (ret == size) Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are queue-4.7/drm-edid-add-6-bpc-quirk-for-display-aeo-model-0.patch queue-4.7/drm-aux-transfer-can-return-0-deal-with-it.patch queue-4.7/drm-i915-update-cdclk_freq-register-on-bdw-after-changing-cdclk-frequency.patch