This patch fixes the problem on some HP desktop machines with eDP which give blank screens after S3 resume. The problem looks like a timing issue. Although BLC_PWM_CPU_CTL register is already restored at the beginning of resume, it doesn't seem to take effect. Simply re-issuing the register write restores the backlight gracefully. Tested with 3.5-rc3 kernel. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=49233 Signed-off-by: Takashi Iwai <tiwai at suse.de> --- drivers/gpu/drm/i915/i915_drv.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 9fe9ebe..2ba1350 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -658,6 +658,9 @@ static int i915_drm_thaw(struct drm_device *dev) intel_opregion_init(dev); + if (dev_priv->backlight) + backlight_update_status(dev_priv->backlight); + dev_priv->modeset_on_lid = 0; console_lock(); -- 1.7.10.4
