1 files changed, 32 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 6a54f1cfa125..4f1cf8afe25f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -250,6 +250,10 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector);
 static void handle_hpd_rx_irq(void *param);
 
+static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
+					 int bl_idx,
+					 u32 user_brightness);
+
 static bool
 is_timing_unchanged_for_freesync(struct drm_crtc_state *old_crtc_state,
 				 struct drm_crtc_state *new_crtc_state);
@@ -3137,6 +3141,21 @@ static void hpd_rx_irq_work_suspend(struct amdgpu_display_manager *dm)
 	}
 }
 
+static int dm_prepare_suspend(struct amdgpu_ip_block *ip_block)
+{
+	struct amdgpu_device *adev = ip_block->adev;
+
+	if (amdgpu_in_reset(adev))
+		return 0;
+
+	WARN_ON(adev->dm.cached_state);
+	adev->dm.cached_state = drm_atomic_helper_suspend(adev_to_drm(adev));
+	if (IS_ERR(adev->dm.cached_state))
+		return PTR_ERR(adev->dm.cached_state);
+
+	return 0;
+}
+
 static int dm_suspend(struct amdgpu_ip_block *ip_block)
 {
 	struct amdgpu_device *adev = ip_block->adev;
@@ -3167,10 +3186,11 @@ static int dm_suspend(struct amdgpu_ip_block *ip_block)
 		return 0;
 	}
 
-	WARN_ON(adev->dm.cached_state);
-	adev->dm.cached_state = drm_atomic_helper_suspend(adev_to_drm(adev));
-	if (IS_ERR(adev->dm.cached_state))
-		return PTR_ERR(adev->dm.cached_state);
+	if (!adev->dm.cached_state) {
+		adev->dm.cached_state = drm_atomic_helper_suspend(adev_to_drm(adev));
+		if (IS_ERR(adev->dm.cached_state))
+			return PTR_ERR(adev->dm.cached_state);
+	}
 
 	s3_handle_hdmi_cec(adev_to_drm(adev), true);
 
@@ -3432,6 +3452,12 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
 
 		mutex_unlock(&dm->dc_lock);
 
+		/* set the backlight after a reset */
+		for (i = 0; i < dm->num_of_edps; i++) {
+			if (dm->backlight_dev[i])
+				amdgpu_dm_backlight_set_level(dm, i, dm->brightness[i]);
+		}
+
 		return 0;
 	}
 
@@ -3596,6 +3622,7 @@ static const struct amd_ip_funcs amdgpu_dm_funcs = {
 	.early_fini = amdgpu_dm_early_fini,
 	.hw_init = dm_hw_init,
 	.hw_fini = dm_hw_fini,
+	.prepare_suspend = dm_prepare_suspend,
 	.suspend = dm_suspend,
 	.resume = dm_resume,
 	.is_idle = dm_is_idle,
@@ -4986,6 +5013,7 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector)
 	dm->backlight_dev[aconnector->bl_idx] =
 		backlight_device_register(bl_name, aconnector->base.kdev, dm,
 					  &amdgpu_dm_backlight_ops, &props);
+	dm->brightness[aconnector->bl_idx] = props.brightness;
 
 	if (IS_ERR(dm->backlight_dev[aconnector->bl_idx])) {
 		DRM_ERROR("DM: Backlight registration failed!\n");
@@ -5053,7 +5081,6 @@ static void setup_backlight_device(struct amdgpu_display_manager *dm,
 	aconnector->bl_idx = bl_idx;
 
 	amdgpu_dm_update_backlight_caps(dm, bl_idx);
-	dm->brightness[bl_idx] = AMDGPU_MAX_BL_LEVEL;
 	dm->backlight_link[bl_idx] = link;
 	dm->num_of_edps++;