drm/radeon: Fix backlight control on iMac 12,1
authorNicholas Bishop <nicholasbishop@google.com>
Fri, 11 Feb 2022 19:57:39 +0000 (14:57 -0500)
committerAlex Deucher <alexander.deucher@amd.com>
Mon, 14 Feb 2022 20:08:41 +0000 (15:08 -0500)
The iMac 12,1 does not use the gmux driver for backlight, so the radeon
backlight device is needed to set the brightness.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1838
Signed-off-by: Nicholas Bishop <nicholasbishop@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/radeon/atombios_encoders.c

index 0fce73b..70bd84b 100644 (file)
@@ -198,7 +198,8 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder,
         * so don't register a backlight device
         */
        if ((rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) &&
-           (rdev->pdev->device == 0x6741))
+           (rdev->pdev->device == 0x6741) &&
+           !dmi_match(DMI_PRODUCT_NAME, "iMac12,1"))
                return;
 
        if (!radeon_encoder->enc_priv)