usb: musb: fix remote wakeup racing with suspend

[mirror_ubuntu-bionic-kernel.git] / drivers / usb / musb / musb_virthub.c

diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c
index 5165d2b07ade01985d2e9b104552b33d92850f47..2f8dd9826e9481a99e28f16a65be89e1e13a8955 100644 (file)
--- a/drivers/usb/musb/musb_virthub.c
+++ b/drivers/usb/musb/musb_virthub.c
@@ -48,14 +48,14 @@ void musb_host_finish_resume(struct work_struct *work)
        spin_unlock_irqrestore(&musb->lock, flags);
 }
 
-void musb_port_suspend(struct musb *musb, bool do_suspend)
+int musb_port_suspend(struct musb *musb, bool do_suspend)
 {
        struct usb_otg  *otg = musb->xceiv->otg;
        u8              power;
        void __iomem    *mbase = musb->mregs;
 
        if (!is_host_active(musb))
-               return;
+               return 0;
 
        /* NOTE:  this doesn't necessarily put PHY into low power mode,
         * turning off its clock; that's a function of PHY integration and
@@ -66,16 +66,20 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
        if (do_suspend) {
                int retries = 10000;
 
-               power &= ~MUSB_POWER_RESUME;
-               power |= MUSB_POWER_SUSPENDM;
-               musb_writeb(mbase, MUSB_POWER, power);
+               if (power & MUSB_POWER_RESUME)
+                       return -EBUSY;
 
-               /* Needed for OPT A tests */
-               power = musb_readb(mbase, MUSB_POWER);
-               while (power & MUSB_POWER_SUSPENDM) {
+               if (!(power & MUSB_POWER_SUSPENDM)) {
+                       power |= MUSB_POWER_SUSPENDM;
+                       musb_writeb(mbase, MUSB_POWER, power);
+
+                       /* Needed for OPT A tests */
                        power = musb_readb(mbase, MUSB_POWER);
-                       if (retries-- < 1)
-                               break;
+                       while (power & MUSB_POWER_SUSPENDM) {
+                               power = musb_readb(mbase, MUSB_POWER);
+                               if (retries-- < 1)
+                                       break;
+                       }
                }
 
                musb_dbg(musb, "Root port suspended, power %02x", power);
@@ -111,6 +115,7 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
                schedule_delayed_work(&musb->finish_resume_work,
                                      msecs_to_jiffies(USB_RESUME_TIMEOUT));
        }
+       return 0;
 }
 
 void musb_port_reset(struct musb *musb, bool do_reset)