From: Daniel Vetter Date: Tue, 22 May 2012 19:41:25 +0000 (+0200) Subject: drm/i915: wait for a vblank to pass after tv detect X-Git-Tag: v3.5-rc1~40^2~2^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf2125e2f7e931b50a6c76ba0435ba001409ccbf;p=pandora-kernel.git drm/i915: wait for a vblank to pass after tv detect 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 Cc: stable@vger.kernel.org Acked-by: Chris Wilson Signed-Off-by: Daniel Vetter --- Reading git-diff-tree failed