[ 085/103] drm/radeon: add backlight quirk for hybrid mac

[Greg Kroah-Hartman]

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

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

From: Alex Deucher <alexander.deucher@xxxxxxx>

commit 80101790670385a85aca35ecae4b89e3f2fceecc upstream.

Mac laptops with multiple GPUs apparently use the gmux
driver for backlight control.  Don't register a radeon
backlight interface.  We may need to add other pci ids
for other hybrid mac laptops.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=65377

Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/radeon/atombios_encoders.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -186,6 +186,13 @@ void radeon_atom_backlight_init(struct r
 	u8 backlight_level;
 	char bl_name[16];
 
+	/* Mac laptops with multiple GPUs use the gmux driver for backlight
+	 * so don't register a backlight device
+	 */
+	if ((rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) &&
+	    (rdev->pdev->device == 0x6741))
+		return;
+
 	if (!radeon_encoder->enc_priv)
 		return;
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/