[PATCH 3.16.y-ckt 084/183] ACPI / video: Add disable_native_backlight quirk for Dell XPS15 L521X

[Luis Henriques]

3.16.7-ckt8 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans de Goede <hdegoede at redhat.com>

commit 6a3ef10bacb08860805e9053f919786dc34760ba upstream.

The L521X variant of the Dell XPS15 has integrated nvidia graphics, and
backlight control does not work properly when using the native interfaces.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1163574
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/acpi/video.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 28fa58c11e56..b7bed5fdc433 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -711,6 +711,16 @@ static struct dmi_system_id video_dmi_table[] __initdata = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "370R4E/370R4V/370R5E/3570RE/370R5V"),
 		},
 	},
+
+	{
+	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
+	 .callback = video_disable_native_backlight,
+	 .ident = "Dell XPS15 L521X",
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
+		},
+	},
 	{}
 };