[PATCH 34/93] ACPI / video: ignore BIOS initial backlight value for HP m4

[Luis Henriques]

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

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

From: Alex Hung <alex.hung at canonical.com>

commit fedbe9bc6fd3e14b1ffbb3dac407777ac4a3650c upstream.

On HP m4 lapops, BIOS reports minimum backlight on boot and
causes backlight to dim completely. This ignores the initial backlight
values and set to max brightness.

References: https://bugs.launchpad.net/bugs/1184501
Signed-off-by: Alex Hung <alex.hung at canonical.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 | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 55c9ae7..a4d9f5d 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -463,6 +463,14 @@ static struct dmi_system_id video_dmi_table[] __initdata = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "HP 1000 Notebook PC"),
 		},
 	},
+	{
+	 .callback = video_ignore_initial_backlight,
+	 .ident = "HP Pavilion m4",
+	 .matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion m4 Notebook PC"),
+		},
+	},
 	{}
 };
 
-- 
1.8.1.2