drm/radeon: add backlight quirk for hybrid mac
authorAlex Deucher <alexander.deucher@amd.com>
Mon, 10 Jun 2013 13:57:07 +0000 (09:57 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Jul 2013 21:07:41 +0000 (14:07 -0700)
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>
drivers/gpu/drm/radeon/atombios_encoders.c

index 8406c82..4120d35 100644 (file)
@@ -186,6 +186,13 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder,
        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;