From patchwork Tue Jul 7 22:16:15 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 492631 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id DDDB3140D19; Wed, 8 Jul 2015 08:17:41 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZCbBK-0001S1-1Y; Tue, 07 Jul 2015 22:17:38 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZCbA3-0000fd-6u for kernel-team@lists.ubuntu.com; Tue, 07 Jul 2015 22:16:19 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZCbA2-0000Yl-MZ; Tue, 07 Jul 2015 22:16:18 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1ZCbA0-0002h3-FJ; Tue, 07 Jul 2015 15:16:16 -0700 From: Kamal Mostafa To: Jim Bride Subject: [3.13.y-ckt stable] Patch "drm/i915/hsw: Fix workaround for server AUX channel clock divisor" has been added to staging queue Date: Tue, 7 Jul 2015 15:16:15 -0700 Message-Id: <1436307375-10323-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 X-Extended-Stable: 3.13 Cc: Jani Nikula , Kamal Mostafa , kernel-team@lists.ubuntu.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled drm/i915/hsw: Fix workaround for server AUX channel clock divisor to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt23. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From c5c69638032f3898933351bc85c7e4bfe9e170eb Mon Sep 17 00:00:00 2001 From: Jim Bride Date: Wed, 27 May 2015 10:21:48 -0700 Subject: drm/i915/hsw: Fix workaround for server AUX channel clock divisor commit e058c945e03a629c99606452a6931f632dd28903 upstream. According to the HSW b-spec we need to try clock divisors of 63 and 72, each 3 or more times, when attempting DP AUX channel communication on a server chipset. This actually wasn't happening due to a short-circuit that only checked the DP_AUX_CH_CTL_DONE bit in status rather than checking that the operation was done and that DP_AUX_CH_CTL_TIME_OUT_ERROR was not set. [v2] Implemented alternate solution suggested by Jani Nikula. Signed-off-by: Jim Bride Signed-off-by: Jani Nikula Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/i915/intel_dp.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) -- 1.9.1 diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6b50a14..4ac4a41 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -481,10 +481,8 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, DP_AUX_CH_CTL_RECEIVE_ERROR)) continue; if (status & DP_AUX_CH_CTL_DONE) - break; + goto done; } - if (status & DP_AUX_CH_CTL_DONE) - break; } if ((status & DP_AUX_CH_CTL_DONE) == 0) { @@ -493,6 +491,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, goto out; } +done: /* Check for timeout or receive error. * Timeouts occur when the sink is not connected */