drm/radeon: add backlight quirk for hybrid mac
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@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 8406c82..4120d35 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -186,6 +186,13 @@
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;