From 2e7eeeb59a92d09144fdb7d2dc1af77a10a7945b Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Mon, 9 Jun 2014 18:24:34 +0300 Subject: [PATCH] drm/i915: set backlight duty cycle after backlight enable for gen4 For reasons I can't claim to fully understand gen4 seems to require backlight duty cycle setting after the backlight has been enabled, or else black screen follows. I don't have documentation for the correct sequence on gen4 either. Confirmed on Dell Latitude D630 and MacBook4,1. This fixes a regression introduced by commit b35684b8fa94e04f55fd38bf672b737741d2f9e2 Author: Jani Nikula Date: Thu Nov 14 12:13:41 2013 +0200 drm/i915: do full backlight setup at enable time Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75791 Reported-and-tested-by: mcy@lm7.fr Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79423 Reported-and-tested-by: Marc Milgram Cc: Stable # 3.14+ Acked-by: Daniel Vetter Signed-off-by: Jani Nikula --- Reading git-format-patch failed