From patchwork Mon Jul 14 19:10:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Todd Previte X-Patchwork-Id: 4548781 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0B0029F295 for ; Mon, 14 Jul 2014 19:11:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 49DAF20158 for ; Mon, 14 Jul 2014 19:11:43 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 8C8582011E for ; Mon, 14 Jul 2014 19:11:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 28D1E6E476; Mon, 14 Jul 2014 12:11:42 -0700 (PDT) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by gabe.freedesktop.org (Postfix) with ESMTP id 475416E471 for ; Mon, 14 Jul 2014 12:11:39 -0700 (PDT) Received: by mail-pd0-f178.google.com with SMTP id r10so5637442pdi.23 for ; Mon, 14 Jul 2014 12:11:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=HS6Rc88yScDs8zWzGqdJptti4lNB8NbjP7NPmsKwmWw=; b=mYqAfQ39b3x/o10relmGrddLY85oEJB3b1HBI+XWAvwtYnsIv/7OLW1Jg5zORzpkjB Tt/LSyFTxqNWQcRt3/Gi5hxgyOIk1/U4tsUKYa4lj9qM2VnqQ58HfTwThGa99WVcUh6F SiuoNnXLBDpuoopueBCpGK+euXw2jCuBeiKxKXcRdkcSYonSr7NuofLJwiON/MRulpf4 EVtC7bRG8inX7WyoeSTa0fUJfnq8EL4qjQdWfJKP5mI4Y1SJLP9WLRcOkGws9I34fehW nXYvLZ2GspmKq2hnKkuumcOroJuevTxK5MxXBQAnoof5zpP2Noc+CaG1c/2Jklr5HyTy Z1fQ== X-Received: by 10.68.164.100 with SMTP id yp4mr2767653pbb.136.1405365099163; Mon, 14 Jul 2014 12:11:39 -0700 (PDT) Received: from localhost.localdomain (ip72-201-95-47.ph.ph.cox.net. [72.201.95.47]) by mx.google.com with ESMTPSA id z5sm8049888pbt.81.2014.07.14.12.11.37 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 14 Jul 2014 12:11:38 -0700 (PDT) From: Todd Previte To: intel-gfx@lists.freedesktop.org Date: Mon, 14 Jul 2014 12:10:47 -0700 Message-Id: <1405365047-6866-13-git-send-email-tprevite@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1405365047-6866-1-git-send-email-tprevite@gmail.com> References: <1405365047-6866-1-git-send-email-tprevite@gmail.com> Subject: [Intel-gfx] [PATCH 12/12] drm/i915: Add a delay in Displayport AUX transactions for compliance testing X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The Displayport Link Layer Compliance Testing Specification 1.2 rev 1.1 specifies that repeated AUX transactions after a failure (NACK, DEFER or no response) must have a minimum delay of 400us before the resend can occur. Tests 4.2.1.1 and 4.2.1.2 are two tests that require this specifically. Signed-off-by: Todd Previte --- drivers/gpu/drm/i915/intel_dp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 0e207aaf..f0664cd 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -573,8 +573,12 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, DP_AUX_CH_CTL_RECEIVE_ERROR); if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR)) + DP_AUX_CH_CTL_RECEIVE_ERROR)) { + /* DP compliance requires 400us delay for errors/timeouts + (DP CTS 1.2 Core Rev 1.1, 4.2.1.1 & 4.2.1.2) */ + udelay(400); continue; + } if (status & DP_AUX_CH_CTL_DONE) break; }