Merge tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux

Pull fbdev fixes from Bartlomiej Zolnierkiewicz:

 - fix probing time checks in omapfb driver (regression fix)

 - fix optional VBAT support in ssd1307fb driver (regression fix)

 - fix connecting to backend in xen-fbfront driver

* tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux:
  fbdev: omapfb: delete check_required_callbacks()
  xen, fbfront: fix connecting to backend
  fbdev/ssd1307fb: fix optional VBAT support

drivers/video/fbdev/omap/omapfb_main.c

@@ -1608,19 +1608,6 @@ static int omapfb_find_ctrl(struct omapfb_device *fbdev)
 	return 0;
 }
 
-static void check_required_callbacks(struct omapfb_device *fbdev)
-{
-#define _C(x) (fbdev->ctrl->x != NULL)
-#define _P(x) (fbdev->panel->x != NULL)
-	BUG_ON(fbdev->ctrl == NULL || fbdev->panel == NULL);
-	BUG_ON(!(_C(init) && _C(cleanup) && _C(get_caps) &&
-		 _C(set_update_mode) && _C(setup_plane) && _C(enable_plane) &&
-		 _P(init) && _P(cleanup) && _P(enable) && _P(disable) &&
-		 _P(get_caps)));
-#undef _P
-#undef _C
-}
-
 /*
  * Called by LDM binding to probe and attach a new device.
  * Initialization sequence:
@@ -1705,8 +1692,6 @@ static int omapfb_do_probe(struct platform_device *pdev,
 		omapfb_ops.fb_mmap = omapfb_mmap;
 	init_state++;
 
-	check_required_callbacks(fbdev);
-
 	r = planes_init(fbdev);
 	if (r)
 		goto cleanup;

drivers/video/fbdev/ssd1307fb.c

@@ -578,11 +578,15 @@ static int ssd1307fb_probe(struct i2c_client *client,
 
 	par->vbat_reg = devm_regulator_get_optional(&client->dev, "vbat");
 	if (IS_ERR(par->vbat_reg)) {
-		dev_err(&client->dev, "failed to get VBAT regulator: %ld\n",
-			PTR_ERR(par->vbat_reg));
 		ret = PTR_ERR(par->vbat_reg);
+		if (ret == -ENODEV) {
+			par->vbat_reg = NULL;
+		} else {
+			dev_err(&client->dev, "failed to get VBAT regulator: %d\n",
+				ret);
 			goto fb_alloc_error;
 		}
+	}
 
 	if (of_property_read_u32(node, "solomon,width", &par->width))
 		par->width = 96;
@@ -668,11 +672,14 @@ static int ssd1307fb_probe(struct i2c_client *client,
 		udelay(4);
 	}
 
+	if (par->vbat_reg) {
 		ret = regulator_enable(par->vbat_reg);
 		if (ret) {
-		dev_err(&client->dev, "failed to enable VBAT: %d\n", ret);
+			dev_err(&client->dev, "failed to enable VBAT: %d\n",
+				ret);
 			goto reset_oled_error;
 		}
+	}
 
 	ret = ssd1307fb_init(par);
 	if (ret)
@@ -710,6 +717,7 @@ static int ssd1307fb_probe(struct i2c_client *client,
 		pwm_put(par->pwm);
 	};
 regulator_enable_error:
+	if (par->vbat_reg)
 		regulator_disable(par->vbat_reg);
 reset_oled_error:
 	fb_deferred_io_cleanup(info);

drivers/video/fbdev/xen-fbfront.c

@@ -643,7 +643,6 @@ static void xenfb_backend_changed(struct xenbus_device *dev,
 		break;
 
 	case XenbusStateInitWait:
-InitWait:
 		xenbus_switch_state(dev, XenbusStateConnected);
 		break;
 
@@ -654,7 +653,8 @@ static void xenfb_backend_changed(struct xenbus_device *dev,
 		 * get Connected twice here.
 		 */
 		if (dev->state != XenbusStateConnected)
-			goto InitWait; /* no InitWait seen yet, fudge it */
+			/* no InitWait seen yet, fudge it */
+			xenbus_switch_state(dev, XenbusStateConnected);
 
 		if (xenbus_read_unsigned(info->xbdev->otherend,
 					 "request-update", 0))