3.6.11.9-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleksij Rempel [ Upstream commit d66eaf9f89502971fddcb0de550b01fa6f409d83 ] in some cases where device is attched to xhci port and do not responding, for example ath9k_htc with stalled firmware, kernel will crash on ring_doorbell_for_active_rings. This patch check if pointer exist before it is used. This patch should be backported to kernels as old as 2.6.35, that contain the commit e9df17eb1408cfafa3d1844bfc7f22c7237b31b8 "USB: xhci: Correct assumptions about number of rings per endpoint" Signed-off-by: Oleksij Rempel Signed-off-by: Sarah Sharp Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt --- drivers/usb/host/xhci-ring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 8848616..21a01ac 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -434,7 +434,7 @@ static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci, /* A ring has pending URBs if its TD list is not empty */ if (!(ep->ep_state & EP_HAS_STREAMS)) { - if (!(list_empty(&ep->ring->td_list))) + if (ep->ring && !(list_empty(&ep->ring->td_list))) xhci_ring_ep_doorbell(xhci, slot_id, ep_index, 0); return; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/