--- a/drivers/usb/host/ehci-dbg.c +++ b/drivers/usb/host/ehci-dbg.c @@ -763,9 +763,7 @@ show_registers (struct class_device *class_dev, char *buf) } if (ehci->reclaim) { - temp = scnprintf (next, size, "reclaim qh %p%s\n", - ehci->reclaim, - ehci->reclaim_ready ? " ready" : ""); + temp = scnprintf(next, size, "reclaim qh %p\n", ehci->reclaim); size -= temp; next += temp; } diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 5f2d74e..da5e035 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -109,7 +109,7 @@ static const char hcd_name [] = "ehci_hcd"; #define EHCI_TUNE_MULT_TT 1 #define EHCI_TUNE_FLS 2 /* (small) 256 frame schedule */ -#define EHCI_IAA_JIFFIES (HZ/100) /* arbitrary; ~10 msec */ +#define EHCI_IAA_MSECS 10 /* arbitrary */ #define EHCI_IO_JIFFIES (HZ/10) /* io watchdog > irq_thresh */ #define EHCI_ASYNC_JIFFIES (HZ/20) /* async idle timeout */ #define EHCI_SHRINK_JIFFIES (HZ/200) /* async qh unlink delay */ @@ -266,6 +266,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci) /*-------------------------------------------------------------------------*/ +static void end_unlink_async(struct ehci_hcd *ehci); static void ehci_work(struct ehci_hcd *ehci); #include "ehci-hub.c" @@ -275,25 +276,62 @@ static void ehci_work(struct ehci_hcd *ehci); /*-------------------------------------------------------------------------*/ -static void ehci_watchdog (unsigned long param) +static void ehci_iaa_watchdog(unsigned long param) { struct ehci_hcd *ehci = (struct ehci_hcd *) param; unsigned long flags; spin_lock_irqsave (&ehci->lock, flags); - /* lost IAA irqs wedge things badly; seen with a vt8235 */ - if (ehci->reclaim) { - u32 status = ehci_readl(ehci, &ehci->regs->status); - if (status & STS_IAA) { - ehci_vdbg (ehci, "lost IAA\n"); + /* Lost IAA irqs wedge things badly; seen first with a vt8235. + * So we need this watchdog, but must protect it against both + * (a) SMP races against real IAA firing and retriggering, and + * (b) clean HC shutdown, when IAA watchdog was pending. + */ + if (ehci->reclaim + && !timer_pending(&ehci->iaa_watchdog) + && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) { + u32 cmd, status; + + /* If we get here, IAA is *REALLY* late. It's barely + * conceivable that the system is so busy that CMD_IAAD + * is still legitimately set, so let's be sure it's + * clear before we read STS_IAA. (The HC should clear + * CMD_IAAD when it sets STS_IAA.) + */ + cmd = ehci_readl(ehci, &ehci->regs->command); + if (cmd & CMD_IAAD) + ehci_writel(ehci, cmd & ~CMD_IAAD, + &ehci->regs->command); + + /* If IAA is set here it either legitimately triggered + * before we cleared IAAD above (but _way_ late, so we'll + * still count it as lost) ... or a silicon erratum: + * - VIA seems to set IAA without triggering the IRQ; + * - IAAD potentially cleared without setting IAA. + */ + status = ehci_readl(ehci, &ehci->regs->status); + if ((status & STS_IAA) || !(cmd & CMD_IAAD)) { COUNT (ehci->stats.lost_iaa); ehci_writel(ehci, STS_IAA, &ehci->regs->status); - ehci->reclaim_ready = 1; } + + ehci_vdbg(ehci, "IAA watchdog: status %x cmd %x\n", + status, cmd); + end_unlink_async(ehci); } - /* stop async processing after it's idled a bit */ + spin_unlock_irqrestore(&ehci->lock, flags); +} + +static void ehci_watchdog(unsigned long param) +{ + struct ehci_hcd *ehci = (struct ehci_hcd *) param; + unsigned long flags; + + spin_lock_irqsave(&ehci->lock, flags); + + /* stop async processing after it's idled a bit */ if (test_bit (TIMER_ASYNC_OFF, &ehci->actions)) start_unlink_async (ehci, ehci->async); @@ -363,8 +401,6 @@ static void ehci_port_power (struct ehci_hcd *ehci, int is_on) static void ehci_work (struct ehci_hcd *ehci) { timer_action_done (ehci, TIMER_IO_WATCHDOG); - if (ehci->reclaim_ready) - end_unlink_async (ehci); /* another CPU may drop ehci->lock during a schedule scan while * it reports urb completions. this flag guards against bogus @@ -399,6 +435,7 @@ static void ehci_stop (struct usb_hcd *hcd) /* no more interrupts ... */ del_timer_sync (&ehci->watchdog); + del_timer_sync(&ehci->iaa_watchdog); spin_lock_irq(&ehci->lock); if (HC_IS_RUNNING (hcd->state)) @@ -447,6 +484,10 @@ static int ehci_init(struct usb_hcd *hcd) ehci->watchdog.function = ehci_watchdog; ehci->watchdog.data = (unsigned long) ehci; + init_timer(&ehci->iaa_watchdog); + ehci->iaa_watchdog.function = ehci_iaa_watchdog; + ehci->iaa_watchdog.data = (unsigned long) ehci; + /* * hw default: 1K periodic list heads, one per frame. * periodic_size can shrink by USBCMD update if hcc_params allows. @@ -463,7 +504,6 @@ static int ehci_init(struct usb_hcd *hcd) ehci->i_thresh = 2 + HCC_ISOC_THRES(hcc_params); ehci->reclaim = NULL; - ehci->reclaim_ready = 0; ehci->next_uframe = -1; /* @@ -611,7 +651,7 @@ static int ehci_run (struct usb_hcd *hcd) static irqreturn_t ehci_irq (struct usb_hcd *hcd) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); - u32 status, pcd_status = 0; + u32 status, pcd_status = 0, cmd; int bh; spin_lock (&ehci->lock); @@ -632,7 +672,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) /* clear (just) interrupts */ ehci_writel(ehci, status, &ehci->regs->status); - ehci_readl(ehci, &ehci->regs->command); /* unblock posted write */ + cmd = ehci_readl(ehci, &ehci->regs->command); bh = 0; #ifdef EHCI_VERBOSE_DEBUG @@ -653,9 +693,17 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) /* complete the unlinking of some qh [4.15.2.3] */ if (status & STS_IAA) { - COUNT (ehci->stats.reclaim); - ehci->reclaim_ready = 1; - bh = 1; + /* guard against (alleged) silicon errata */ + if (cmd & CMD_IAAD) { + ehci_writel(ehci, cmd & ~CMD_IAAD, + &ehci->regs->command); + ehci_dbg(ehci, "IAA with IAAD still set?\n"); + } + if (ehci->reclaim) { + COUNT(ehci->stats.reclaim); + end_unlink_async(ehci); + } else + ehci_dbg(ehci, "IAA with nothing to reclaim?\n"); } /* remote wakeup [4.3.1] */ @@ -761,10 +809,16 @@ static int ehci_urb_enqueue ( static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) { - /* if we need to use IAA and it's busy, defer */ - if (qh->qh_state == QH_STATE_LINKED - && ehci->reclaim - && HC_IS_RUNNING (ehci_to_hcd(ehci)->state)) { + /* failfast */ + if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state) && ehci->reclaim) + end_unlink_async(ehci); + + /* if it's not linked then there's nothing to do */ + if (qh->qh_state != QH_STATE_LINKED) + ; + + /* defer till later if busy */ + else if (ehci->reclaim) { struct ehci_qh *last; for (last = ehci->reclaim; @@ -774,12 +828,8 @@ static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) qh->qh_state = QH_STATE_UNLINK_WAIT; last->reclaim = qh; - /* bypass IAA if the hc can't care */ - } else if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state) && ehci->reclaim) - end_unlink_async (ehci); - - /* something else might have unlinked the qh by now */ - if (qh->qh_state == QH_STATE_LINKED) + /* start IAA cycle */ + } else start_unlink_async (ehci, qh); } @@ -806,7 +856,19 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) qh = (struct ehci_qh *) urb->hcpriv; if (!qh) break; - unlink_async (ehci, qh); + switch (qh->qh_state) { + case QH_STATE_LINKED: + case QH_STATE_COMPLETING: + unlink_async(ehci, qh); + break; + case QH_STATE_UNLINK: + case QH_STATE_UNLINK_WAIT: + /* already started */ + break; + case QH_STATE_IDLE: + WARN_ON(1); + break; + } break; case PIPE_INTERRUPT: @@ -898,6 +960,7 @@ rescan: unlink_async (ehci, qh); /* FALL THROUGH */ case QH_STATE_UNLINK: /* wait for hw to finish? */ + case QH_STATE_UNLINK_WAIT: idle_timeout: spin_unlock_irqrestore (&ehci->lock, flags); schedule_timeout_uninterruptible(1); diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 735db4a..80c1de8 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -123,6 +123,8 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) if (time_before (jiffies, ehci->next_statechange)) msleep(5); + del_timer_sync(&ehci->watchdog); + del_timer_sync(&ehci->iaa_watchdog); port = HCS_N_PORTS (ehci->hcs_params); spin_lock_irq (&ehci->lock); @@ -134,7 +136,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) } ehci->command = ehci_readl(ehci, &ehci->regs->command); if (ehci->reclaim) - ehci->reclaim_ready = 1; + end_unlink_async(ehci); ehci_work(ehci); /* Unlike other USB host controller types, EHCI doesn't have @@ -171,7 +173,6 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) } /* turn off now-idle HC */ - del_timer_sync (&ehci->watchdog); ehci_halt (ehci); hcd->state = HC_STATE_SUSPENDED; diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index ad0d496..7e3350f 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -305,7 +305,7 @@ static int ehci_pci_resume(struct usb_hcd *hcd) /* emptying the schedule aborts any urbs */ spin_lock_irq(&ehci->lock); if (ehci->reclaim) - ehci->reclaim_ready = 1; + end_unlink_async(ehci); ehci_work(ehci); spin_unlock_irq(&ehci->lock); diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index b10f39c..853e5e6 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -973,7 +973,7 @@ static void end_unlink_async (struct ehci_hcd *ehci) struct ehci_qh *qh = ehci->reclaim; struct ehci_qh *next; - timer_action_done (ehci, TIMER_IAA_WATCHDOG); + iaa_watchdog_done(ehci); // qh->hw_next = cpu_to_hc32(qh->qh_dma); qh->qh_state = QH_STATE_IDLE; @@ -983,7 +983,6 @@ static void end_unlink_async (struct ehci_hcd *ehci) /* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */ next = qh->reclaim; ehci->reclaim = next; - ehci->reclaim_ready = 0; qh->reclaim = NULL; qh_completions (ehci, qh); @@ -1059,11 +1058,10 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) return; } - ehci->reclaim_ready = 0; cmd |= CMD_IAAD; ehci_writel(ehci, cmd, &ehci->regs->command); (void)ehci_readl(ehci, &ehci->regs->command); - timer_action (ehci, TIMER_IAA_WATCHDOG); + iaa_watchdog_start(ehci); } /*-------------------------------------------------------------------------*/ diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 951d69f..3d41731 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -74,7 +74,6 @@ struct ehci_hcd { /* one per controller */ /* async schedule support */ struct ehci_qh *async; struct ehci_qh *reclaim; - unsigned reclaim_ready : 1; unsigned scanning : 1; /* periodic schedule support */ @@ -105,6 +104,7 @@ struct ehci_hcd { /* one per controller */ struct dma_pool *itd_pool; /* itd per iso urb */ struct dma_pool *sitd_pool; /* sitd per split iso urb */ + struct timer_list iaa_watchdog; struct timer_list watchdog; unsigned long actions; unsigned stamp; @@ -140,9 +140,21 @@ static inline struct usb_hcd *ehci_to_hcd (struct ehci_hcd *ehci) } +static inline void +iaa_watchdog_start(struct ehci_hcd *ehci) +{ + WARN_ON(timer_pending(&ehci->iaa_watchdog)); + mod_timer(&ehci->iaa_watchdog, + jiffies + msecs_to_jiffies(EHCI_IAA_MSECS)); +} + +static inline void iaa_watchdog_done(struct ehci_hcd *ehci) +{ + del_timer(&ehci->iaa_watchdog); +} + enum ehci_timer_action { TIMER_IO_WATCHDOG, - TIMER_IAA_WATCHDOG, TIMER_ASYNC_SHRINK, TIMER_ASYNC_OFF, }; @@ -160,9 +172,6 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action) unsigned long t; switch (action) { - case TIMER_IAA_WATCHDOG: - t = EHCI_IAA_JIFFIES; - break; case TIMER_IO_WATCHDOG: t = EHCI_IO_JIFFIES; break; @@ -179,8 +188,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action) // async queue SHRINK often precedes IAA. while it's ready // to go OFF neither can matter, and afterwards the IO // watchdog stops unless there's still periodic traffic. - if (action != TIMER_IAA_WATCHDOG - && t > ehci->watchdog.expires + if (time_before_eq(t, ehci->watchdog.expires) && timer_pending (&ehci->watchdog)) return; mod_timer (&ehci->watchdog, t);