[PATCH 3.13.y-ckt 017/121] acer-wmi: Add acpi_backlight=video quirk for the Acer KAV80

From: Kamal Mostafa
Date: Tue Dec 02 2014 - 14:58:46 EST

3.13.11-ckt12 -stable review patch. If anyone has any objections, please let me know.


From: Hans de Goede <hdegoede@xxxxxxxxxx>

commit 183fd8fcd7f8afb7ac5ec68f83194872f9fecc84 upstream.

The acpi-video backlight interface on the Acer KAV80 is broken, and worse
it causes the entire machine to slow down significantly after a suspend/resume.

Blacklist it, and use the acer-wmi backlight interface instead. Note that
the KAV80 is somewhat unique in that it is the only Acer model where we
fall back to acer-wmi after blacklisting, rather then using the native
(e.g. intel) backlight driver. This is done because there is no native
backlight interface on this model.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1128309
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
drivers/platform/x86/acer-wmi.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 3990c79..b942a1b 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -580,6 +580,17 @@ static const struct dmi_system_id video_vendor_dmi_table[] = {
+ {
+ /*
+ * Note no video_set_backlight_video_vendor, we must use the
+ * acer interface, as there is no native backlight interface.
+ */
+ .ident = "Acer KAV80",
+ .matches = {
+ },
+ },


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