USB: xhci: Use GFP_ATOMIC while holding spinlocks.

The xHCI functions to queue an URB onto the hardware rings must be called
with the xhci spinlock held.  Those functions will allocate memory, and
take a gfp_t memory flags argument.  We must pass them the GFP_ATOMIC
flag, since we don't want the memory allocation to attempt to sleep while
waiting for more memory to become available.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 1c5901a..ff99365 100644 (file)
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -601,10 +601,13 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
                goto exit;
        }
        if (usb_endpoint_xfer_control(&urb->ep->desc))
-               ret = xhci_queue_ctrl_tx(xhci, mem_flags, urb,
+               /* We have a spinlock and interrupts disabled, so we must pass
+                * atomic context to this function, which may allocate memory.
+                */
+               ret = xhci_queue_ctrl_tx(xhci, GFP_ATOMIC, urb,
                                slot_id, ep_index);
        else if (usb_endpoint_xfer_bulk(&urb->ep->desc))
-               ret = xhci_queue_bulk_tx(xhci, mem_flags, urb,
+               ret = xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb,
                                slot_id, ep_index);
        else
                ret = -EINVAL;