---

yaml
---
r: 317020
b: refs/heads/master
c: d58b4bc
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c0c53dbc32ea05a1e1dd9dba4772327da9a11750
+refs/heads/master: d58b4bcc6df8046cf9c3c59f9ff84d2cd86b93eb

trunk/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);

trunk/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;
 }
 

trunk/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;
+}

trunk/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;