drm/amdgpu: Restore LCD backlight level on resume

Instead of only enabling the backlight (which seems to set it to max
brightness), just re-set the current backlight level, which also takes
care of enabling the backlight if necessary.

Port of radeon commit:
drm/radeon: Restore LCD backlight level on resume (>= R5xx)

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

diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
index cd6edc4..1e0bba2 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
@@ -1279,8 +1279,7 @@ amdgpu_atombios_encoder_setup_dig(struct drm_encoder *encoder, int action)
                        amdgpu_atombios_encoder_setup_dig_encoder(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
                }
                if (amdgpu_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT))
-                       amdgpu_atombios_encoder_setup_dig_transmitter(encoder,
-                                                              ATOM_TRANSMITTER_ACTION_LCD_BLON, 0, 0);
+                       amdgpu_atombios_encoder_set_backlight_level(amdgpu_encoder, dig->backlight_level);
                if (ext_encoder)
                        amdgpu_atombios_encoder_setup_external_encoder(encoder, ext_encoder, ATOM_ENABLE);
        } else {