[Intel-gfx] [PATCH] i915: Fix bug where screen brightness is not restored

[Takashi Iwai]

At Tue, 15 Nov 2011 11:58:38 -0800,
Kamal Mostafa wrote:
> 
> [1  <multipart/signed (7bit)>]
> [1.1  <text/plain; UTF-8 (quoted-printable)>]
> On Mon, 2011-11-14 at 18:42 -0800, Alex Davis wrote:
> > From: Alex Davis<alex14641 at yahoo.com>
> > 
> > This patch fixes an issue where the screen would remain dark when
> > 
> > a key was pressed when the laptop lid was reopened or after the
> > laptop had gone into power-save mode.
> 
> [cross-posting to intel-gfx]
> 
> Keith, also note that Alex and I did respond to your request to test the
> already committed patch "drm/i915/panel: Always record the backlight
> level again (but cleverly)".  We both determined that patch does *not*
> fix the problem.  Alex's patch below does fix it.

My rough guess is the inconsistency of property taken during the
backlight disabled.  How about the patch below (untested!) in addition
to the fix in 3.2?


Takashi

---
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 499d4c0..21f60b7 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -326,7 +326,8 @@ static int intel_panel_update_status(struct backlight_device *bd)
 static int intel_panel_get_brightness(struct backlight_device *bd)
 {
 	struct drm_device *dev = bl_get_data(bd);
-	return intel_panel_get_backlight(dev);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	return dev_priv->backlight_level;
 }
 
 static const struct backlight_ops intel_panel_bl_ops = {