releases/3.19.2/drm-radeon-enable-native-backlight-control-on-old-macs.patch

   1 From 7a26f9ad1b5badfd0200ce2262ad696e2a6b7fbb Mon Sep 17 00:00:00 2001
   2 From: "Nathan-J. Hirschauer" <nathanhi@deepserve.info>
   3 Date: Wed, 18 Feb 2015 02:01:19 +0100
   4 Subject: drm/radeon: enable native backlight control on old macs
   5
   6 From: "Nathan-J. Hirschauer" <nathanhi@deepserve.info>
   7
   8 commit 7a26f9ad1b5badfd0200ce2262ad696e2a6b7fbb upstream.
   9
  10 Commit b7bc596ebbe0 ("drm/radeon: disable native
  11 backlight control on pre-r6xx asics (v2)") accidently
  12 broke backlight control on old mac laptops that use the
  13 on-GPU backlight controller.
  14
  15 Signed-off-by: Nathan-J. Hirschauer <nathanhi@deepserve.info>
  16 Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  drivers/gpu/drm/radeon/radeon_encoders.c |    3 +++
  21  1 file changed, 3 insertions(+)
  22
  23 --- a/drivers/gpu/drm/radeon/radeon_encoders.c
  24 +++ b/drivers/gpu/drm/radeon/radeon_encoders.c
  25 @@ -179,9 +179,12 @@ static void radeon_encoder_add_backlight
  26                     (rdev->pdev->subsystem_vendor == 0x1734) &&
  27                     (rdev->pdev->subsystem_device == 0x1107))
  28                         use_bl = false;
  29 +/* Older PPC macs use on-GPU backlight controller */
  30 +#ifndef CONFIG_PPC_PMAC
  31                 /* disable native backlight control on older asics */
  32                 else if (rdev->family < CHIP_R600)
  33                         use_bl = false;
  34 +#endif
  35                 else
  36                         use_bl = true;
  37         }