diff options
Diffstat (limited to 'payloads/libpayload/drivers/usb')
| -rw-r--r-- | payloads/libpayload/drivers/usb/ehci.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/payloads/libpayload/drivers/usb/ehci.c b/payloads/libpayload/drivers/usb/ehci.c index 4ff137e40b..6a1cfb5791 100644 --- a/payloads/libpayload/drivers/usb/ehci.c +++ b/payloads/libpayload/drivers/usb/ehci.c @@ -626,8 +626,14 @@ static u8 *ehci_poll_intr_queue(void *const queue) intrq->head = intrq->head->next; } /* reset queue if we fully processed it after underrun */ - else if (intrq->qh.td.next_qtd & QTD_TERMINATE) { + else if ((intrq->qh.td.next_qtd & QTD_TERMINATE) && + /* to prevent race conditions: + not our head and not active */ + (intrq->qh.current_td_ptr != + virt_to_phys(&intrq->head->td)) && + !(intrq->qh.td.token & QTD_ACTIVE)) { usb_debug("resetting underrun ehci interrupt queue.\n"); + intrq->qh.current_td_ptr = 0; memset((void *)&intrq->qh.td, 0, sizeof(intrq->qh.td)); intrq->qh.td.next_qtd = virt_to_phys(&intrq->head->td); } |