Commit a061a5a0 authored Jul 22, 2010 by Andiry Xu Committed by Greg Kroah-Hartman Aug 10, 2010

USB: xHCI: allocate bigger ring for isochronous endpoint

Isochronous endpoint needs a bigger size of transfer ring. Isochronous URB
consists of multiple packets, each packet needs a isoc td to carry, and
there will be multiple trbs inserted to the ring at one time. One segment
is too small for isochronous endpoints, and it will result in
room_on_ring() check failure and the URB is failed to enqueue.

Allocate bigger ring for isochronous endpoint. 8 segments should be enough.
This will be replaced with dynamic ring expansion in the future.

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

parent 04e51901

drivers/usb/host/xhci-mem.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -1112,6 +1112,16 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
		ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);

		/* Set up the endpoint ring */
		/*
		* Isochronous endpoint ring needs bigger size because one isoc URB
		* carries multiple packets and it will insert multiple tds to the
		* ring.
		* This should be replaced with dynamic ring resizing in the future.
		*/
		if (usb_endpoint_xfer_isoc(&ep->desc))
		virt_dev->eps[ep_index].new_ring =
		xhci_ring_alloc(xhci, 8, true, mem_flags);
		else
		virt_dev->eps[ep_index].new_ring =
		xhci_ring_alloc(xhci, 1, true, mem_flags);
		if (!virt_dev->eps[ep_index].new_ring) {

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