Commit 04b38670 authored Nov 16, 2011 by Takashi Iwai Committed by Keith Packard Nov 17, 2011

drm/i915: Fix inconsistent backlight level during disabled

When the brightness property is inquired while the backlight is disabled,
the driver returns a wrong value (zero) because it probes the value after
the backlight was turned off.  This caused a black screen even after the
backlight is enabled again.  It should return the internal backlight_level
instead, so that it won't be influenced by the backlight-enable state.

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=41926
BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/872652



Tested-by: Kamal Mostafa <kamal@canonical.com>
Cc: Alex Davis <alex14641@yahoo.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Keith Packard <keithp@keithp.com>

parent 457eafce

drivers/gpu/drm/i915/intel_panel.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 = {