diff options
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 15 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 3 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-timer.c | 106 | ||||
| -rw-r--r-- | drivers/usb/host/ehci.h | 16 |
4 files changed, 138 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index bc94822f4c5d..f8fed163a23a 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -30,8 +30,7 @@ #include <linux/vmalloc.h> #include <linux/errno.h> #include <linux/init.h> -#include <linux/timer.h> -#include <linux/ktime.h> +#include <linux/hrtimer.h> #include <linux/list.h> #include <linux/interrupt.h> #include <linux/usb.h> @@ -380,6 +379,7 @@ 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-timer.c" #include "ehci-hub.c" #include "ehci-lpm.c" #include "ehci-mem.c" @@ -494,7 +494,10 @@ static void ehci_shutdown(struct usb_hcd *hcd) spin_lock_irq(&ehci->lock); ehci->rh_state = EHCI_RH_STOPPING; ehci_silence_controller(ehci); + ehci->enabled_hrtimer_events = 0; spin_unlock_irq(&ehci->lock); + + hrtimer_cancel(&ehci->hrtimer); } static void ehci_port_power (struct ehci_hcd *ehci, int is_on) @@ -561,12 +564,14 @@ static void ehci_stop (struct usb_hcd *hcd) del_timer_sync(&ehci->iaa_watchdog); spin_lock_irq(&ehci->lock); + ehci->enabled_hrtimer_events = 0; ehci_quiesce(ehci); ehci_silence_controller(ehci); ehci_reset (ehci); spin_unlock_irq(&ehci->lock); + hrtimer_cancel(&ehci->hrtimer); remove_sysfs_files(ehci); remove_debug_files (ehci); @@ -615,6 +620,10 @@ static int ehci_init(struct usb_hcd *hcd) ehci->iaa_watchdog.function = ehci_iaa_watchdog; ehci->iaa_watchdog.data = (unsigned long) ehci; + hrtimer_init(&ehci->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + ehci->hrtimer.function = ehci_hrtimer_func; + ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT; + hcc_params = ehci_readl(ehci, &ehci->caps->hcc_params); /* @@ -954,6 +963,8 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) dbg_status(ehci, "fatal", status); ehci_halt(ehci); dead: + ehci->enabled_hrtimer_events = 0; + hrtimer_try_to_cancel(&ehci->hrtimer); ehci_reset(ehci); ehci_writel(ehci, 0, &ehci->regs->configured_flag); usb_hc_died(hcd); diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index fb1b99e74937..25329e4b844f 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -311,12 +311,15 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) ehci_readl(ehci, &ehci->regs->intr_enable); ehci->next_statechange = jiffies + msecs_to_jiffies(10); + ehci->enabled_hrtimer_events = 0; + ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT; spin_unlock_irq (&ehci->lock); /* ehci_work() may have re-enabled the watchdog timer, which we do not * want, and so we must delete any pending watchdog timer events. */ del_timer_sync(&ehci->watchdog); + hrtimer_cancel(&ehci->hrtimer); return 0; } diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c new file mode 100644 index 000000000000..f6279e2883a8 --- /dev/null +++ b/drivers/usb/host/ehci-timer.c @@ -0,0 +1,106 @@ +/* + * Copyright (C) 2012 by Alan Stern + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +/* This file is part of ehci-hcd.c */ + +/*-------------------------------------------------------------------------*/ + +/* + * EHCI timer support... Now using hrtimers. + * + * Lots of different events are triggered from ehci->hrtimer. Whenever + * the timer routine runs, it checks each possible event; events that are + * currently enabled and whose expiration time has passed get handled. + * The set of enabled events is stored as a collection of bitflags in + * ehci->enabled_hrtimer_events, and they are numbered in order of + * increasing delay values (ranging between 1 ms and 100 ms). + * + * Rather than implementing a sorted list or tree of all pending events, + * we keep track only of the lowest-numbered pending event, in + * ehci->next_hrtimer_event. Whenever ehci->hrtimer gets restarted, its + * expiration time is set to the timeout value for this event. + * + * As a result, events might not get handled right away; the actual delay + * could be anywhere up to twice the requested delay. This doesn't + * matter, because none of the events are especially time-critical. The + * ones that matter most all have a delay of 1 ms, so they will be + * handled after 2 ms at most, which is okay. In addition to this, we + * allow for an expiration range of 1 ms. + */ + +/* + * Delay lengths for the hrtimer event types. + * Keep this list sorted by delay length, in the same order as + * the event types indexed by enum ehci_hrtimer_event in ehci.h. + */ +static unsigned event_delays_ns[] = { +}; + +/* Enable a pending hrtimer event */ +static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event, + bool resched) +{ + ktime_t *timeout = &ehci->hr_timeouts[event]; + + if (resched) + *timeout = ktime_add(ktime_get(), + ktime_set(0, event_delays_ns[event])); + ehci->enabled_hrtimer_events |= (1 << event); + + /* Track only the lowest-numbered pending event */ + if (event < ehci->next_hrtimer_event) { + ehci->next_hrtimer_event = event; + hrtimer_start_range_ns(&ehci->hrtimer, *timeout, + NSEC_PER_MSEC, HRTIMER_MODE_ABS); + } +} + + +/* + * Handler functions for the hrtimer event types. + * Keep this array in the same order as the event types indexed by + * enum ehci_hrtimer_event in ehci.h. + */ +static void (*event_handlers[])(struct ehci_hcd *) = { +}; + +static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t) +{ + struct ehci_hcd *ehci = container_of(t, struct ehci_hcd, hrtimer); + ktime_t now; + unsigned long events; + unsigned long flags; + unsigned e; + + spin_lock_irqsave(&ehci->lock, flags); + + events = ehci->enabled_hrtimer_events; + ehci->enabled_hrtimer_events = 0; + ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT; + + /* + * Check each pending event. If its time has expired, handle + * the event; otherwise re-enable it. + */ + now = ktime_get(); + for_each_set_bit(e, &events, EHCI_HRTIMER_NUM_EVENTS) { + if (now.tv64 >= ehci->hr_timeouts[e].tv64) + event_handlers[e](ehci); + else + ehci_enable_event(ehci, e, false); + } + + spin_unlock_irqrestore(&ehci->lock, flags); + return HRTIMER_NORESTART; +} diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 9e8e82ecce58..070be83028d5 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -73,7 +73,23 @@ enum ehci_rh_state { EHCI_RH_STOPPING }; +/* + * Timer events, ordered by increasing delay length. + * Always update event_delays_ns[] and event_handlers[] (defined in + * ehci-timer.c) in parallel with this list. + */ +enum ehci_hrtimer_event { + EHCI_HRTIMER_NUM_EVENTS /* Must come last */ +}; +#define EHCI_HRTIMER_NO_EVENT 99 + struct ehci_hcd { /* one per controller */ + /* timing support */ + enum ehci_hrtimer_event next_hrtimer_event; + unsigned enabled_hrtimer_events; + ktime_t hr_timeouts[EHCI_HRTIMER_NUM_EVENTS]; + struct hrtimer hrtimer; + /* glue to PCI and HCD framework */ struct ehci_caps __iomem *caps; struct ehci_regs __iomem *regs; |