diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 84c41262109c..a93d445b63a4 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -566,6 +566,9 @@ static int ehci_init(struct usb_hcd *hcd) /* Accept arbitrarily long scatter-gather lists */ if (!(hcd->driver->flags & HCD_LOCAL_MEM)) hcd->self.sg_tablesize = ~0; + + /* Prepare for unlinking active QHs */ + ehci->old_current = ~0; return 0; } diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 15dcae8f0631..a24341ef863d 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -1341,14 +1341,60 @@ static void end_unlink_async(struct ehci_hcd *ehci) * after the IAA interrupt occurs. In self-defense, always go * through two IAA cycles for each QH. */ - else if (qh->qh_state == QH_STATE_UNLINK_WAIT) { + else if (qh->qh_state == QH_STATE_UNLINK) { + /* + * Second IAA cycle has finished. Process only the first + * waiting QH (NVIDIA (?) bug). + */ + list_move_tail(&qh->unlink_node, &ehci->async_idle); + } + + /* + * AMD/ATI (?) bug: The HC can continue to use an active QH long + * after the IAA interrupt occurs. To prevent problems, QHs that + * may still be active will wait until 2 ms have passed with no + * change to the hw_current and hw_token fields (this delay occurs + * between the two IAA cycles). + * + * The EHCI spec (4.8.2) says that active QHs must not be removed + * from the async schedule and recommends waiting until the QH + * goes inactive. This is ridiculous because the QH will _never_ + * become inactive if the endpoint NAKs indefinitely. + */ + + /* Some reasons for unlinking guarantee the QH can't be active */ + else if (qh->unlink_reason & (QH_UNLINK_HALTED | + QH_UNLINK_SHORT_READ | QH_UNLINK_DUMMY_OVERLAY)) + goto DelayDone; + + /* The QH can't be active if the queue was and still is empty... */ + else if ((qh->unlink_reason & QH_UNLINK_QUEUE_EMPTY) && + list_empty(&qh->qtd_list)) + goto DelayDone; + + /* ... or if the QH has halted */ + else if (qh->hw->hw_token & cpu_to_hc32(ehci, QTD_STS_HALT)) + goto DelayDone; + + /* Otherwise we have to wait until the QH stops changing */ + else { + __hc32 qh_current, qh_token; + + qh_current = qh->hw->hw_current; + qh_token = qh->hw->hw_token; + if (qh_current != ehci->old_current || + qh_token != ehci->old_token) { + ehci->old_current = qh_current; + ehci->old_token = qh_token; + ehci_enable_event(ehci, + EHCI_HRTIMER_ACTIVE_UNLINK, true); + return; + } + DelayDone: qh->qh_state = QH_STATE_UNLINK; early_exit = true; } - - /* Otherwise process only the first waiting QH (NVIDIA bug?) */ - else - list_move_tail(&qh->unlink_node, &ehci->async_idle); + ehci->old_current = ~0; /* Prepare for next QH */ /* Start a new IAA cycle if any QHs are waiting for it */ if (!list_empty(&ehci->async_unlink)) diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c index 6bea4d553ec5..69f50e6533a6 100644 --- a/drivers/usb/host/ehci-timer.c +++ b/drivers/usb/host/ehci-timer.c @@ -72,6 +72,7 @@ static unsigned event_delays_ns[] = { 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_DEAD */ 1125 * NSEC_PER_USEC, /* EHCI_HRTIMER_UNLINK_INTR */ 2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_FREE_ITDS */ + 2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ACTIVE_UNLINK */ 5 * NSEC_PER_MSEC, /* EHCI_HRTIMER_START_UNLINK_INTR */ 6 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ASYNC_UNLINKS */ 10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IAA_WATCHDOG */ @@ -395,6 +396,7 @@ static void (*event_handlers[])(struct ehci_hcd *) = { ehci_handle_controller_death, /* EHCI_HRTIMER_POLL_DEAD */ ehci_handle_intr_unlinks, /* EHCI_HRTIMER_UNLINK_INTR */ end_free_itds, /* EHCI_HRTIMER_FREE_ITDS */ + end_unlink_async, /* EHCI_HRTIMER_ACTIVE_UNLINK */ ehci_handle_start_intr_unlinks, /* EHCI_HRTIMER_START_UNLINK_INTR */ unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */ ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */ diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index f11b9dc53981..b13894550139 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -110,6 +110,7 @@ enum ehci_hrtimer_event { EHCI_HRTIMER_POLL_DEAD, /* Wait for dead controller to stop */ EHCI_HRTIMER_UNLINK_INTR, /* Wait for interrupt QH unlink */ EHCI_HRTIMER_FREE_ITDS, /* Wait for unused iTDs and siTDs */ + EHCI_HRTIMER_ACTIVE_UNLINK, /* Wait while unlinking an active QH */ EHCI_HRTIMER_START_UNLINK_INTR, /* Unlink empty interrupt QHs */ EHCI_HRTIMER_ASYNC_UNLINKS, /* Unlink empty async QHs */ EHCI_HRTIMER_IAA_WATCHDOG, /* Handle lost IAA interrupts */ @@ -156,6 +157,8 @@ struct ehci_hcd { /* one per controller */ struct list_head async_idle; unsigned async_unlink_cycle; unsigned async_count; /* async activity count */ + __hc32 old_current; /* Test for QH becoming */ + __hc32 old_token; /* inactive during unlink */ /* periodic schedule support */ #define DEFAULT_I_TDPS 1024 /* some HCs can do less */