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>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 338cd1611ab3a24981676194811bebb0ef836120..0112353ec97d02913051022a9da2295b763e90c2 100644 (file)
--- 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,
 };
 
 /*-------------------------------------------------------------------------*/