From patchwork Fri Jul 1 22:22:51 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesse Barnes X-Patchwork-Id: 939312 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p61MXkZU022804 for ; Fri, 1 Jul 2011 22:34:09 GMT Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2EBEBA096A for ; Fri, 1 Jul 2011 15:23:24 -0700 (PDT) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from oproxy7-pub.bluehost.com (oproxy7-pub.bluehost.com [67.222.55.9]) by gabe.freedesktop.org (Postfix) with SMTP id F3D249E7E7 for ; Fri, 1 Jul 2011 15:23:02 -0700 (PDT) Received: (qmail 12055 invoked by uid 0); 1 Jul 2011 22:23:02 -0000 Received: from unknown (HELO box514.bluehost.com) (74.220.219.114) by oproxy7.bluehost.com with SMTP; 1 Jul 2011 22:23:02 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=virtuousgeek.org; h=Received:From:To:Cc:Subject:Date:Message-Id:X-Mailer:In-Reply-To:References:X-Identified-User; b=NL/Mn14rTSGfTbBvZEo5uKI5yYWNRkGyTK+xUTbc9YWJia885FpFNpsjFT8hz7XlV03gVIrheuDtnE6E94eGgQSKDIZN7l4sNojrQOqa30eyqkfTinEvnJziRrTn+H0a; Received: from c-67-161-37-189.hsd1.ca.comcast.net ([67.161.37.189] helo=localhost.localdomain) by box514.bluehost.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1Qcm73-00047w-Gn; Fri, 01 Jul 2011 16:23:01 -0600 From: Jesse Barnes To: intel-gfx@lists.freedesktop.org Date: Fri, 1 Jul 2011 15:22:51 -0700 Message-Id: <1309558978-4704-2-git-send-email-jbarnes@virtuousgeek.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1309558978-4704-1-git-send-email-jbarnes@virtuousgeek.org> References: <1309558978-4704-1-git-send-email-jbarnes@virtuousgeek.org> X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 67.161.37.189 authed with jbarnes@virtuousgeek.org} Subject: [Intel-gfx] [PATCH 1/8] drm/i915/dp: retry link status read 3 times on failure X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Fri, 01 Jul 2011 22:34:09 +0000 (UTC) Especially after a hotplug or power status change, the sink may not reply immediately to a link status query. So retry 3 times per the spec to really make sure nothing is there. Signed-off-by: Jesse Barnes --- drivers/gpu/drm/i915/intel_dp.c | 17 +++++++++++++---- 1 files changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 391b55f..1829ecc 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1019,13 +1019,22 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode) static bool intel_dp_get_link_status(struct intel_dp *intel_dp) { - int ret; + int ret, i; + + /* Must try AUX reads for this at least 3 times */ + for (i = 0; i < 3; i++) { + ret = intel_dp_aux_native_read(intel_dp, + DP_LANE0_1_STATUS, + intel_dp->link_status, + DP_LINK_STATUS_SIZE); + if (ret == DP_LINK_STATUS_SIZE) + break; + msleep(1); + } - ret = intel_dp_aux_native_read(intel_dp, - DP_LANE0_1_STATUS, - intel_dp->link_status, DP_LINK_STATUS_SIZE); if (ret != DP_LINK_STATUS_SIZE) return false; + return true; }