xhci: Use GFP_NOIO during device reset. (a6d940dd) · Commits · 戴 / test

When xhci_discover_or_reset_device() is called after a host controller power loss, the virtual device may need to be reallocated. Make sure xhci_alloc_dev() uses GFP_NOIO. This avoid causing a deadlock by allowing the kernel to flush pending I/O while reallocating memory for a virtual device for a USB mass storage device that's holding the backing store for dirty memory buffers. This patch should be queued for the 2.6.37 stable tree. Signed-off-by:

Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable@kernel.org

drivers/usb/host/xhci.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -2431,8 +2431,12 @@ int xhci_alloc_dev(struct usb_hcd hcd, struct usb_device udev)
		xhci_err(xhci, "Error while assigning device slot ID\n");
		return 0;
		}
		/* xhci_alloc_virt_device() does not touch rings; no need to lock */
		if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_KERNEL)) {
		/* xhci_alloc_virt_device() does not touch rings; no need to lock.
		* Use GFP_NOIO, since this function can be called from
		* xhci_discover_or_reset_device(), which may be called as part of
		* mass storage driver error handling.
		*/
		if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_NOIO)) {
		/* Disable slot, if we can do it without mem alloc */
		xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
		spin_lock_irqsave(&xhci->lock, flags);

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