[051/200] USB: xhci: Fix issue with set interface after stall.
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From: Greg KH on 1 Jul 2010 18:00 2.6.34-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarah Sharp <sarah.a.sharp(a)linux.intel.com> commit 1624ae1c19e227096ba85bfc389d9b99cb6f7dde upstream. When the USB core installs a new interface, it unconditionally clears the halts on all the endpoints on the new interface. Usually the xHCI host needs to know when an endpoint is reset, so it can change its internal endpoint state. In this case, it doesn't care, because the endpoints were never halted in the first place. To avoid issuing a redundant Reset Endpoint command, the xHCI driver looks at xhci_virt_ep->stopped_td to determine if the endpoint was actually halted. However, the functions that handle the stall never set that variable to NULL after it dealt with the stall. So if an endpoint stalled and a Reset Endpoint command completed, and then the class driver tried to install a new alternate setting, the xHCI driver would access the old xhci_virt_ep->stopped_td pointer. A similar problem occurs if the endpoint has been stopped to cancel a transfer. Signed-off-by: Sarah Sharp <sarah.a.sharp(a)linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- drivers/usb/host/xhci-ring.c | 7 +++++++ drivers/usb/host/xhci.c | 2 ++ 2 files changed, 9 insertions(+) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -578,6 +578,8 @@ static void handle_stopped_endpoint(stru /* Otherwise just ring the doorbell to restart the ring */ ring_ep_doorbell(xhci, slot_id, ep_index); } + ep->stopped_td = NULL; + ep->stopped_trb = NULL; /* * Drop the lock and complete the URBs in the cancelled TD list. @@ -1061,8 +1063,13 @@ static void xhci_cleanup_halted_endpoint ep->ep_state |= EP_HALTED; ep->stopped_td = td; ep->stopped_trb = event_trb; + xhci_queue_reset_ep(xhci, slot_id, ep_index); xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index); + + ep->stopped_td = NULL; + ep->stopped_trb = NULL; + xhci_ring_cmd_db(xhci); } --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1438,6 +1438,8 @@ void xhci_endpoint_reset(struct usb_hcd kfree(virt_ep->stopped_td); xhci_ring_cmd_db(xhci); } + virt_ep->stopped_td = NULL; + virt_ep->stopped_trb = NULL; spin_unlock_irqrestore(&xhci->lock, flags); if (ret) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |