USB: musb: fix possible panic while resuming

During driver resume processing, musb could cause a kernel panic.
Fix by enabling the clock earlier, with the resume_early method.

Signed-off-by: Kim Kyuwon <q1.kim@samsung.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 8 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 338cd1611ab3..0112353ec97d 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2170,26 +2170,22 @@ static int musb_suspend(struct platform_device *pdev, pm_message_t message)
         return 0;
 }
 
-static int musb_resume(struct platform_device *pdev)
+static int musb_resume_early(struct platform_device *pdev)
 {
-        unsigned long   flags;
         struct musb     *musb = dev_to_musb(&pdev->dev);
 
         if (!musb->clock)
                 return 0;
 
-        spin_lock_irqsave(&musb->lock, flags);
-
         if (musb->set_clock)
                 musb->set_clock(musb->clock, 1);
         else
                 clk_enable(musb->clock);
 
         /* for static cmos like DaVinci, register values were preserved
-         * unless for some reason the whole soc powered down and we're
-         * not treating that as a whole-system restart (e.g. swsusp)
+         * unless for some reason the whole soc powered down or the USB
+         * module got reset through the PSC (vs just being disabled).
          */
-        spin_unlock_irqrestore(&musb->lock, flags);
         return 0;
 }
 
@@ -2207,7 +2203,7 @@ static struct platform_driver musb_driver = {
         .remove         = __devexit_p(musb_remove),
         .shutdown       = musb_shutdown,
         .suspend        = musb_suspend,
-        .resume         = musb_resume,
+        .resume_early   = musb_resume_early,
 };
 
 /*-------------------------------------------------------------------------*/