drm/radeon: fix dpms when driver backlight control is disabled

If driver backlight control is disabled, either by driver
parameter or default per-asic setting, revert to the old behavior.

Fixes a regression in commit:
4281f46ef839050d2ef60348f661eb463c21cc2e

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

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 933fd1bc849bb7e934be6a9cd6d8216c1a15f110..bb292143997ee8ccce3e6e6898edba2a5eeb12b6 100644 (file)
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1625,9 +1625,14 @@ radeon_atom_encoder_dpms_avivo(struct drm_encoder *encoder, int mode)
                } else
                        atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
                if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
-                       struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
+                       if (rdev->mode_info.bl_encoder) {
+                               struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 
-                       atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+                               atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+                       } else {
+                               args.ucAction = ATOM_LCD_BLON;
+                               atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+                       }
                }
                break;
        case DRM_MODE_DPMS_STANDBY:
@@ -1707,8 +1712,13 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
                        if (ASIC_IS_DCE4(rdev))
                                atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
                }
-               if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT))
-                       atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+               if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
+                       if (rdev->mode_info.bl_encoder)
+                               atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+                       else
+                               atombios_dig_transmitter_setup(encoder,
+                                                              ATOM_TRANSMITTER_ACTION_LCD_BLON, 0, 0);
+               }
                if (ext_encoder)
                        atombios_external_encoder_setup(encoder, ext_encoder, ATOM_ENABLE);
                break;