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Commit 74bb3508 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
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USB: musb_host, minor enqueue locking fix (v2) 



Someone noted that the enqueue path used an unlocked access
for usb_host_endpoint->hcpriv ... fix that, by being safe
and always accessing it under spinlock protection.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e13c594f

drivers/usb/musb/musb_host.c

+8 −9
Original line number Original line Diff line number Diff line
@@ -1841,7 +1841,7 @@ static int musb_urb_enqueue( 
	unsigned long			flags;

	unsigned long			flags;

	struct musb			*musb = hcd_to_musb(hcd);

	struct musb			*musb = hcd_to_musb(hcd);

	struct usb_host_endpoint	*hep = urb->ep;

	struct usb_host_endpoint	*hep = urb->ep;

	struct musb_qh			*qh = hep->hcpriv;

	struct musb_qh			*qh;

	struct usb_endpoint_descriptor	*epd = &hep->desc;

	struct usb_endpoint_descriptor	*epd = &hep->desc;

	int				ret;

	int				ret;

	unsigned			type_reg;

	unsigned			type_reg;
@@ -1853,22 +1853,21 @@ static int musb_urb_enqueue( 




	spin_lock_irqsave(&musb->lock, flags);

	spin_lock_irqsave(&musb->lock, flags);

	ret = usb_hcd_link_urb_to_ep(hcd, urb);

	ret = usb_hcd_link_urb_to_ep(hcd, urb);

	qh = ret ? NULL : hep->hcpriv;

	if (qh)

		urb->hcpriv = qh;

	spin_unlock_irqrestore(&musb->lock, flags);

	spin_unlock_irqrestore(&musb->lock, flags);

	if (ret)

		return ret;





	/* DMA mapping was already done, if needed, and this urb is on

	/* DMA mapping was already done, if needed, and this urb is on

	 * hep->urb_list ... so there's little to do unless hep wasn't

	 * hep->urb_list now ... so we're done, unless hep wasn't yet

	 * yet scheduled onto a live qh.

	 * scheduled onto a live qh.

	 *

	 *

	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets

	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets

	 * disabled, testing for empty qh->ring and avoiding qh setup costs

	 * disabled, testing for empty qh->ring and avoiding qh setup costs

	 * except for the first urb queued after a config change.

	 * except for the first urb queued after a config change.

	 */

	 */

	if (qh) {

	if (qh || ret)

		urb->hcpriv = qh;

		return ret;

		return 0;

	}





	/* Allocate and initialize qh, minimizing the work done each time

	/* Allocate and initialize qh, minimizing the work done each time

	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.

	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.