drm: various FOD fixes:

Revert 716cae3: was a semi-working bandaid to workaround intermittent breakages after 60hz hbm stuck fix.

Mostly revert c5aa78c: Fixed 60hz hbm intermittently stuck after fod, but intermittently broke fod as a result.

Additionally:
 - Only cache backlight value if not HBM.
 - On HBM off, update bl with cached backlight value.
 - Update sde bl scale on fod depress.

The above properly fix and protect against post-FOD high backlight level or HBM at 60hz.

Author: RealJohnGalt

drivers/gpu/drm/msm/dsi-staging/dsi_panel.c

@@ -891,19 +891,39 @@ static int dsi_panel_update_backlight(struct dsi_panel *panel,
 	dsi = &panel->mipi_device;
 	mode = panel->cur_mode;
 
+
+	if (panel->is_hbm_enabled)
+		return 0;
+
 	saved_backlight = bl_lvl;
 
 	if (panel->dc_dim)
 		bl_lvl = 1023;
 
 	if (panel->bl_config.bl_high2bit) {
+		if (HBM_flag == true)
+			return 0;
+
 		if (cur_backlight == bl_lvl && (mode_fps != cur_fps ||
 				 cur_h != panel->cur_mode->timing.h_active)) {
 			cur_fps = mode_fps;
 			cur_h = panel->cur_mode->timing.h_active;
 			return 0;
 		}
 
+		if (hbm_brightness_flag == 1) {
+			count = mode->priv_info->cmd_sets[DSI_CMD_SET_HBM_BRIGHTNESS_OFF].count;
+			if (!count) {
+				pr_debug("This panel does not support HBM brightness off mode.\n");
+				goto error;
+			}
+			else {
+				rc = dsi_panel_tx_cmd_set(panel, DSI_CMD_SET_HBM_BRIGHTNESS_OFF);
+				pr_debug("Send DSI_CMD_SET_HBM_BRIGHTNESS_OFF cmds.\n");
+				hbm_brightness_flag = 0;
+			}
+		}
+
 		rc = mipi_dsi_dcs_set_display_brightness_samsung(dsi, bl_lvl);
 		pr_debug("backlight = %d\n", bl_lvl);
 		cur_backlight = bl_lvl;
@@ -950,8 +970,6 @@ int dsi_panel_op_set_hbm_mode(struct dsi_panel *panel, int level)
 			printk(KERN_DEBUG
 			       "When HBM OFF -->hbm_backight = %d panel->bl_config.bl_level =%d\n",
 			       panel->hbm_backlight, panel->bl_config.bl_level);
-			rc = dsi_panel_update_backlight(panel,
-							panel->hbm_backlight);
 		}
 		break;
 
@@ -5720,7 +5738,7 @@ int dsi_panel_set_hbm_mode(struct dsi_panel *panel, int level)
 				rc = dsi_panel_tx_cmd_set(panel, DSI_CMD_SET_HBM_OFF);
 				pr_debug("Send DSI_CMD_SET_HBM_OFF cmds.\n");
 				pr_debug("hbm_backight = %d, panel->bl_config.bl_level = %d\n",panel->hbm_backlight, panel->bl_config.bl_level);
-				rc= dsi_panel_update_backlight(panel, panel->hbm_backlight);
+				rc = dsi_panel_update_backlight(panel, saved_backlight);
 			}
 			break;
 
@@ -5783,11 +5801,6 @@ int dsi_panel_set_hbm_mode(struct dsi_panel *panel, int level)
 				HBM_flag = true;
 				rc = dsi_panel_tx_cmd_set(panel, DSI_CMD_SET_HBM_ON_5);
 				pr_debug("Send DSI_CMD_SET_HBM_ON_5 cmds.\n");
-				if (rc) {
-					pr_debug("Failed HBM_ON_5, try again.\n");
-					usleep_range(12000, 13000);
-					rc = dsi_panel_tx_cmd_set(panel, DSI_CMD_SET_HBM_ON_5);
-				}
 			}
 			break;
 
@@ -5820,6 +5833,9 @@ int dsi_panel_set_hbm_brightness(struct dsi_panel *panel, int level)
 	dsi = &panel->mipi_device;
 	mode = panel->cur_mode;
 
+	if (panel->is_hbm_enabled)
+		return 0;
+
 	mutex_lock(&panel->panel_lock);
 	if (hbm_brightness_flag == 0) {
 		count = mode->priv_info->cmd_sets[DSI_CMD_SET_HBM_BRIGHTNESS_ON].count;

drivers/gpu/drm/msm/sde/sde_connector.c

@@ -669,6 +669,8 @@ static void sde_connector_pre_update_fod_hbm(struct sde_connector *c_conn)
 				MSM_ENC_VBLANK);
 
 	dsi_panel_set_fod_ui(panel, status);
+	if (!status)
+		_sde_connector_update_bl_scale(c_conn);
 }
 
 int sde_connector_pre_kickoff(struct drm_connector *connector)