usb: musb: Fix broken use of static variable for multiple instances

We can't use static variable first for checking when musb is
initialized when we have multiple musb instances like on am335x.

Tested-by: Ladislav Michl <ladis@linux-mips.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/musb_core.c

@@ -2291,6 +2291,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 	if (status)
 		goto fail5;
 
+	musb->is_initialized = 1;
 	pm_runtime_mark_last_busy(musb->controller);
 	pm_runtime_put_autosuspend(musb->controller);
 
@@ -2629,7 +2630,6 @@ static int musb_runtime_suspend(struct device *dev)
 static int musb_runtime_resume(struct device *dev)
 {
 	struct musb	*musb = dev_to_musb(dev);
-	static int	first = 1;
 
 	/*
 	 * When pm_runtime_get_sync called for the first time in driver
@@ -2640,9 +2640,10 @@ static int musb_runtime_resume(struct device *dev)
 	 * Also context restore without save does not make
 	 * any sense
 	 */
-	if (!first)
-		musb_restore_context(musb);
-	first = 0;
+	if (!musb->is_initialized)
+		return 0;
+
+	musb_restore_context(musb);
 
 	if (musb->need_finish_resume) {
 		musb->need_finish_resume = 0;

drivers/usb/musb/musb_core.h

@@ -385,6 +385,8 @@ struct musb {
 	int			a_wait_bcon;	/* VBUS timeout in msecs */
 	unsigned long		idle_timeout;	/* Next timeout in jiffies */
 
+	unsigned		is_initialized:1;
+
 	/* active means connected and not suspended */
 	unsigned		is_active:1;