Re: [PATCH] drm/radeon: enable native backlight control on old macs

On Tue, 17 Feb 2015, Alex Deucher <alexdeucher_at_gmail.com> wrote:

Commit b7bc596ebbe0cddc97d76ef9309f64471bbf13eb accidently broke backlight control on old mac laptops that use the on-GPU backlight controller.

Reported by nathanhi on IRC.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com> Cc: stable at vger.kernel.org

---

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

diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c

b/drivers/gpu/drm/radeon/radeon_encoders.c

index 6b670b0..275ed45 100644 --- a/drivers/gpu/drm/radeon/radeon_encoders.c +++ b/drivers/gpu/drm/radeon/radeon_encoders.c @@ -179,6 +179,9 @@ static void radeon_encoder_add_backlight(struct

radeon_encoder *radeon_encoder,

         (rdev->pdev->subsystem_vendor == 0x1734) &&
         (rdev->pdev->subsystem_device == 0x1107))
         use_bl = false;

•    /* enable native backlight control on apple */
  

•    else if (rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE)
  

•        use_bl = true;
     /* disable native backlight control on older asics */
     else if (rdev->family < CHIP_R600)
         use_bl = false;
  

-- 1.8.3.1

Hi, thanks for your patch. I've tested it but it didn't won't work as the graphics chip is (unfortunately) detected with PCI_VENDOR_ID_ATI instead of PCI_VENDOR_ID_APPLE. I therefore propose the following patch:

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

diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c index 6b670b0..3a29703 100644 --- 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(struct radeon_encoder *radeon_encoder, (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; }