| Date | Thu, 01 Jul 2010 10:33:46 -0700 | From | Greg KH <> | Subject | [patch 040/164] USB: xhci: Limit bus sg_tablesize to 62 TRBs. |
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2.6.33-stable review patch. If anyone has any objections, please let me know.
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From: Sarah Sharp <sarah.a.sharp@linux.intel.com>
commit bc88d2eba5e19d10dd546e428314909d889b3b6a upstream.
When a scatter-gather list is enqueued to the xHCI driver, it translates each entry into a transfer request block (TRB). Only 63 TRBs can be used per ring segment, and there must be one additional TRB reserved to make sure the hardware does not think the ring is empty (so the enqueue pointer doesn't equal the dequeue pointer). Limit the bus sg_tablesize to 62 TRBs.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/host/xhci-pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -54,7 +54,7 @@ static int xhci_pci_setup(struct usb_hcd struct pci_dev *pdev = to_pci_dev(hcd->self.controller); int retval; - hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 1; + hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2; xhci->cap_regs = hcd->regs; xhci->op_regs = hcd->regs +
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