drm/i915: panel: invert brightness acer aspire 5734z

commit 5a15ab5b93e4a3ebcd4fa6c76cf646a45e9cf806 upstream.

Mark the Acer Aspire 5734Z that this machines requires the module to
invert the panel backlight brightness value after reading from and prior
to writing to the PCI configuration space.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wml: Backported to 3.4: Adjust context]
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 034af1d..1ec9ba1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9201,7 +9201,8 @@
 }
 
 /*
- * A machine may need to invert the panel backlight brightness value
+ * A machine (e.g. Acer Aspire 5734Z) may need to invert the panel backlight
+ * brightness value
  */
 static void quirk_invert_brightness(struct drm_device *dev)
 {
@@ -9242,6 +9243,9 @@
 	/* Sony Vaio Y cannot use SSC on LVDS */
 	{ 0x0046, 0x104d, 0x9076, quirk_ssc_force_disable },
 
+	/* Acer Aspire 5734Z must invert backlight brightness */
+	{ 0x2a42, 0x1025, 0x0459, quirk_invert_brightness },
+
 	/* Dell XPS13 HD Sandy Bridge */
 	{ 0x0116, 0x1028, 0x052e, quirk_no_pcm_pwm_enable },
 	/* Dell XPS13 HD and XPS13 FHD Ivy Bridge */