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usb: musb: PM: fix context save/restore in suspend/resume path

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Currently the driver tries to save context in the suspend path, but
will cause an abort if the device is already runtime suspended.  This
happens, for example, if MUSB loaded/compiled-in, in host mode, but no
USB devices are attached.  MUSB will be runtime suspended, but then
attempting a system suspend will crash due to the context save
being attempted while the device is disabled.

On OMAP, as of v3.1, the driver's ->runtime_suspend() callback will be
called late in the suspend path (by the PM domain layer) if the driver
is not already runtime suspended, ensuring a full shutdown.

Therefore, the context save is not needed in the ->suspend() method
since it will be called in the ->runtime_suspend() method anyways
(similarily for resume.)

NOTE: this leaves the suspend/resume methods basically empty (with
      some FIXMEs and comments, but I'll leave it to the maintainers
      to decide whether to remove them.

Cc: stable@vger.kernel.org
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Kevin Hilman 2011-11-22 17:18:24 -08:00 committed by Greg Kroah-Hartman
parent 118205d6b6
commit 5d193ce8f1
1 changed files with 0 additions and 6 deletions
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6
drivers/usb/musb/musb_core.c
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@ -2301,18 +2301,12 @@ static int musb_suspend(struct device *dev)
*/
}
musb_save_context(musb);
spin_unlock_irqrestore(&musb->lock, flags);
return 0;
}
static int musb_resume_noirq(struct device *dev)
{
struct musb *musb = dev_to_musb(dev);
musb_restore_context(musb);
/* for static cmos like DaVinci, register values were preserved
* unless for some reason the whole soc powered down or the USB
* module got reset through the PSC (vs just being disabled).