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-rw-r--r--drivers/usb/host/ehci-hcd.c16
-rw-r--r--drivers/usb/host/ehci-hub.c1
-rw-r--r--drivers/usb/host/ehci-q.c78
-rw-r--r--drivers/usb/host/ehci-timer.c2
-rw-r--r--drivers/usb/host/ehci.h4
5 files changed, 59 insertions, 42 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 86e8ee1..74ffd20 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -94,8 +94,6 @@ static const char hcd_name [] = "ehci_hcd";
#define EHCI_TUNE_FLS 1 /* (medium) 512-frame schedule */
#define EHCI_IO_JIFFIES (HZ/10) /* io watchdog > irq_thresh */
-#define EHCI_SHRINK_JIFFIES (DIV_ROUND_UP(HZ, 200) + 1)
- /* 5-ms async qh unlink delay */
/* Initial IRQ latency: faster than hw default */
static int log2_irq_thresh = 0; // 0 to 6
@@ -130,15 +128,6 @@ MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");
static void
timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
{
- /* Don't override timeouts which shrink or (later) disable
- * the async ring; just the I/O watchdog. Note that if a
- * SHRINK were pending, OFF would never be requested.
- */
- if (timer_pending(&ehci->watchdog)
- && (BIT(TIMER_ASYNC_SHRINK)
- & ehci->actions))
- return;
-
if (!test_and_set_bit(action, &ehci->actions)) {
unsigned long t;
@@ -148,10 +137,6 @@ timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
return;
t = EHCI_IO_JIFFIES;
break;
- /* case TIMER_ASYNC_SHRINK: */
- default:
- t = EHCI_SHRINK_JIFFIES;
- break;
}
mod_timer(&ehci->watchdog, t + jiffies);
}
@@ -307,6 +292,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci)
/*-------------------------------------------------------------------------*/
static void end_unlink_async(struct ehci_hcd *ehci);
+static void unlink_empty_async(struct ehci_hcd *ehci);
static void ehci_work(struct ehci_hcd *ehci);
static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh);
static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh);
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index a382270..5d84562 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -300,6 +300,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
ehci->rh_state = EHCI_RH_SUSPENDED;
end_unlink_async(ehci);
+ unlink_empty_async(ehci);
ehci_handle_intr_unlinks(ehci);
end_free_itds(ehci);
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 1818329..bae9317 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1205,7 +1205,7 @@ static void start_iaa_cycle(struct ehci_hcd *ehci, bool nested)
end_unlink_async(ehci);
/* Otherwise start a new IAA cycle */
- } else {
+ } else if (likely(ehci->rh_state == EHCI_RH_RUNNING)) {
/* Make sure the unlinks are all visible to the hardware */
wmb();
@@ -1253,6 +1253,39 @@ static void end_unlink_async(struct ehci_hcd *ehci)
}
}
+static void unlink_empty_async(struct ehci_hcd *ehci)
+{
+ struct ehci_qh *qh, *next;
+ bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+ bool check_unlinks_later = false;
+
+ /* Unlink all the async QHs that have been empty for a timer cycle */
+ next = ehci->async->qh_next.qh;
+ while (next) {
+ qh = next;
+ next = qh->qh_next.qh;
+
+ if (list_empty(&qh->qtd_list) &&
+ qh->qh_state == QH_STATE_LINKED) {
+ if (!stopped && qh->unlink_cycle ==
+ ehci->async_unlink_cycle)
+ check_unlinks_later = true;
+ else
+ single_unlink_async(ehci, qh);
+ }
+ }
+
+ /* Start a new IAA cycle if any QHs are waiting for it */
+ if (ehci->async_unlink)
+ start_iaa_cycle(ehci, false);
+
+ /* QHs that haven't been empty for long enough will be handled later */
+ if (check_unlinks_later) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
+ ++ehci->async_unlink_cycle;
+ }
+}
+
/* makes sure the async qh will become idle */
/* caller must own ehci->lock */
@@ -1277,12 +1310,8 @@ static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
static void scan_async (struct ehci_hcd *ehci)
{
- bool stopped;
struct ehci_qh *qh;
- enum ehci_timer_action action = TIMER_IO_WATCHDOG;
-
- timer_action_done (ehci, TIMER_ASYNC_SHRINK);
- stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+ bool check_unlinks_later = false;
ehci->qh_scan_next = ehci->async->qh_next.qh;
while (ehci->qh_scan_next) {
@@ -1301,28 +1330,27 @@ static void scan_async (struct ehci_hcd *ehci)
* in single_unlink_async().
*/
temp = qh_completions(ehci, qh);
- if (qh->needs_rescan)
+ if (qh->needs_rescan) {
start_unlink_async(ehci, qh);
- qh->unlink_time = jiffies + EHCI_SHRINK_JIFFIES;
- if (temp != 0)
+ } else if (list_empty(&qh->qtd_list)
+ && qh->qh_state == QH_STATE_LINKED) {
+ qh->unlink_cycle = ehci->async_unlink_cycle;
+ check_unlinks_later = true;
+ } else if (temp != 0)
goto rescan;
}
+ }
- /* unlink idle entries, reducing DMA usage as well
- * as HCD schedule-scanning costs. delay for any qh
- * we just scanned, there's a not-unusual case that it
- * doesn't stay idle for long.
- * (plus, avoids some kind of re-activation race.)
- */
- if (list_empty(&qh->qtd_list)
- && qh->qh_state == QH_STATE_LINKED) {
- if (!ehci->async_unlink && (stopped ||
- time_after_eq(jiffies, qh->unlink_time)))
- start_unlink_async(ehci, qh);
- else
- action = TIMER_ASYNC_SHRINK;
- }
+ /*
+ * Unlink empty entries, reducing DMA usage as well
+ * as HCD schedule-scanning costs. Delay for any qh
+ * we just scanned, there's a not-unusual case that it
+ * doesn't stay idle for long.
+ */
+ if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING &&
+ !(ehci->enabled_hrtimer_events &
+ BIT(EHCI_HRTIMER_ASYNC_UNLINKS))) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
+ ++ehci->async_unlink_cycle;
}
- if (action == TIMER_ASYNC_SHRINK)
- timer_action (ehci, TIMER_ASYNC_SHRINK);
}
diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index 8ca5f15..a823290 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 */
+ 6 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ASYNC_UNLINKS */
10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IAA_WATCHDOG */
10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_PERIODIC */
15 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_ASYNC */
@@ -347,6 +348,7 @@ 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 */
+ unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */
ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */
ehci_disable_PSE, /* EHCI_HRTIMER_DISABLE_PERIODIC */
ehci_disable_ASE, /* EHCI_HRTIMER_DISABLE_ASYNC */
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 1a78277..303c36c 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -84,6 +84,7 @@ 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_ASYNC_UNLINKS, /* Unlink empty async QHs */
EHCI_HRTIMER_IAA_WATCHDOG, /* Handle lost IAA interrupts */
EHCI_HRTIMER_DISABLE_PERIODIC, /* Wait to disable periodic sched */
EHCI_HRTIMER_DISABLE_ASYNC, /* Wait to disable async sched */
@@ -123,6 +124,7 @@ struct ehci_hcd { /* one per controller */
struct ehci_qh *async_unlink_last;
struct ehci_qh *async_iaa;
struct ehci_qh *qh_scan_next;
+ unsigned async_unlink_cycle;
unsigned async_count; /* async activity count */
/* periodic schedule support */
@@ -232,7 +234,6 @@ static inline struct usb_hcd *ehci_to_hcd (struct ehci_hcd *ehci)
enum ehci_timer_action {
TIMER_IO_WATCHDOG,
- TIMER_ASYNC_SHRINK,
};
static inline void
@@ -382,7 +383,6 @@ struct ehci_qh {
struct ehci_qtd *dummy;
struct ehci_qh *unlink_next; /* next on unlink list */
- unsigned long unlink_time;
unsigned unlink_cycle;
unsigned stamp;
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