[PATCH 3.19 144/177] drm/radeon: enable native backlight control on old macs

Greg Kroah-Hartman
2015-03-16T14:17:43Z

From: "Nathan-J. Hirschauer" <nathanhi@deepserve.info>

commit 7a26f9ad1b5badfd0200ce2262ad696e2a6b7fbb upstream.

Commit b7bc596ebbe0 ("drm/radeon: disable native
backlight control on pre-r6xx asics (v2)") accidently
broke backlight control on old mac laptops that use the
on-GPU backlight controller.

Signed-off-by: Nathan-J. Hirschauer <nathanhi@deepserve.info>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/radeon/radeon_encoders.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/radeon/radeon_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_encoders.c
@@ -179,9 +179,12 @@ static void radeon_encoder_add_backlight
(rdev->pdev->subsystem_vendor == 0x1734) &&
(rdev->pdev->subsystem_device == 0x1107))
use_bl = false;
+/* Older PPC macs use on-GPU backlight controller */
+#ifndef CONFIG_PPC_PMAC
/* disable native backlight control on older asics */
else if (rdev->family < CHIP_R600)
use_bl = false;
+#endif
else
use_bl = true;
}