drm/radeon: add a backlight quirk for Amilo Xi 2550

Only the acpi backlight seems to work.  Using the
radeon backlight controller causes the backlight to
go off.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=81382

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c
index 2a9cd7be9aad736f30a715d5aabd85126ce7416e..15edf23b465c2ba90cca2f2ffb7c242971bda2bf 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_encoders.c
@@ -173,7 +173,14 @@ static void radeon_encoder_add_backlight(struct radeon_encoder *radeon_encoder,
        } else if (radeon_backlight == 1) {
                use_bl = true;
        } else if (radeon_backlight == -1) {
-               use_bl = true;
+               /* Quirks */
+               /* Amilo Xi 2550 only works with acpi bl */
+               if ((rdev->pdev->device == 0x9583) &&
+                   (rdev->pdev->subsystem_vendor == 0x1734) &&
+                   (rdev->pdev->subsystem_device == 0x1107))
+                       use_bl = false;
+               else
+                       use_bl = true;
        }
 
        if (use_bl) {