From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933472Ab2FHFYm (ORCPT ); Fri, 8 Jun 2012 01:24:42 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43204 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761117Ab2FHFHS (ORCPT ); Fri, 8 Jun 2012 01:07:18 -0400 Message-Id: <20120608041842.765027267@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 08 Jun 2012 05:18:54 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Daniel Vetter , Rodrigo Vivi , Chris Wilson Subject: [ 14/82] drm/i915: wait for a vblank to pass after tv detect In-Reply-To: <20120608041840.861504477@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter commit bf2125e2f7e931b50a6c76ba0435ba001409ccbf upstream. Otherwise the hw will get confused and result in a black screen. This regression has been most likely introduce in commit 974b93315b2213b74a42a87e8a9d4fc8c0dbe90c Author: Chris Wilson Date: Sun Sep 5 00:44:20 2010 +0100 drm/i915/tv: Poll for DAC state change That commit replace the first msleep(20) with a busy-loop, but failed to keep the 2nd msleep around. Later on we've replaced all these msleep(20) by proper vblanks. For reference also see the commit in xf86-video-intel: commit 1142be53eb8d2ee8a9b60ace5d49f0ba27332275 Author: Jesse Barnes Date: Mon Jun 9 08:52:59 2008 -0700 Fix TV programming: add vblank wait after TV_CTL writes Fxies FDO bug #14000; we need to wait for vblank after writing TV_CTL or following "DPMS on" calls may not actually enable the output. v2: As suggested by Chris Wilson, add a small comment to ensure that no one accidentally removes this vblank wait again - there really seems to be no sane explanation for why we need it, but it is required. Launchpad: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/763688 Reported-and-Tested-by: Robert Lowery Cc: Rodrigo Vivi Acked-by: Chris Wilson Signed-Off-by: Daniel Vetter Signed-off-by: Ben Hutchings --- drivers/gpu/drm/i915/intel_tv.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c index 3346612..475f6d4 100644 --- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1194,6 +1194,11 @@ intel_tv_detect_type(struct intel_tv *intel_tv, I915_WRITE(TV_DAC, save_tv_dac & ~TVDAC_STATE_CHG_EN); I915_WRITE(TV_CTL, save_tv_ctl); + POSTING_READ(TV_CTL); + + /* For unknown reasons the hw barfs if we don't do this vblank wait. */ + intel_wait_for_vblank(intel_tv->base.base.dev, + to_intel_crtc(intel_tv->base.base.crtc)->pipe); /* Restore interrupt config */ if (connector->polled & DRM_CONNECTOR_POLL_HPD) {