From patchwork Fri Mar 11 15:57:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cpaul@redhat.com X-Patchwork-Id: 8567091 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 43E5FC0554 for ; Fri, 11 Mar 2016 15:58:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 717E32034C for ; Fri, 11 Mar 2016 15:58:13 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 9147D202E9 for ; Fri, 11 Mar 2016 15:58:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9FEAB6EB10; Fri, 11 Mar 2016 15:58:02 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2778B6EB0A; Fri, 11 Mar 2016 15:58:00 +0000 (UTC) Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id BDA5619D39A; Fri, 11 Mar 2016 15:57:59 +0000 (UTC) Received: from ecstaticemu.bos.redhat.com (dhcp-25-74.bos.redhat.com [10.18.25.74]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2BFvumo006821; Fri, 11 Mar 2016 10:57:58 -0500 From: Lyude To: intel-gfx@lists.freedesktop.org Subject: [PATCH 2/2] drm/i915: Retry after 30ms if we fail to resume DP MST Date: Fri, 11 Mar 2016 10:57:02 -0500 Message-Id: <1457711822-20335-3-git-send-email-cpaul@redhat.com> In-Reply-To: <1457711822-20335-1-git-send-email-cpaul@redhat.com> References: <1457711822-20335-1-git-send-email-cpaul@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 Cc: stable@vger.kernel.org, "open list:INTEL DRM DRIVERS excluding Poulsbo, Moorestow..., linux-kernel@vger.kernel.org open list" , Daniel Vetter , Lyude X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 For whatever reason, I've found that some laptops aren't immediately capable of doing aux transactions with their docks when they come out of standby. While I'm still not entirely sure what the cause of this is, sleeping for 30ms and then retrying drm_dp_mst_topology_mgr_resume() should be a sufficient enough workaround until we find a real fix. CC: stable@vger.kernel.org Signed-off-by: Lyude --- drivers/gpu/drm/i915/intel_dp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 1d8de43..8cc5f6f 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -6114,6 +6114,19 @@ void intel_dp_mst_resume(struct drm_device *dev) ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr); if (ret != 0) { + /* + * For some reason, some laptops can't bring + * their MST docks back up immediately after + * resume and need to wait a short period of + * time before aux transactions with the dock + * become functional again. Until we find a + * proper fix for this, this workaround should + * suffice + */ + msleep(30); + ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr); + } + if (ret != 0) { intel_dp_check_mst_status(&intel_dig_port->dp); } }