USB: EHCI: use hrtimer for async schedule

[cascardo/linux.git] / drivers / usb / host / ehci-timer.c

diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index ecd3296..1e907dd 100644 (file)
--- a/drivers/usb/host/ehci-timer.c
+++ b/drivers/usb/host/ehci-timer.c
@@ -67,8 +67,10 @@ static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
  * the event types indexed by enum ehci_hrtimer_event in ehci.h.
  */
 static unsigned event_delays_ns[] = {
+       1 * NSEC_PER_MSEC,      /* EHCI_HRTIMER_POLL_ASS */
        1 * NSEC_PER_MSEC,      /* EHCI_HRTIMER_POLL_PSS */
        10 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_PERIODIC */
+       15 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_ASYNC */
 };
 
 /* Enable a pending hrtimer event */
@@ -91,6 +93,51 @@ static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
 }
 
 
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void ehci_poll_ASS(struct ehci_hcd *ehci)
+{
+       unsigned        actual, want;
+
+       /* Don't enable anything if the controller isn't running (e.g., died) */
+       if (ehci->rh_state != EHCI_RH_RUNNING)
+               return;
+
+       want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
+       actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
+
+       if (want != actual) {
+
+               /* Poll again later, but give up after about 20 ms */
+               if (ehci->ASS_poll_count++ < 20) {
+                       ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
+                       return;
+               }
+               ehci_warn(ehci, "Waited too long for the async schedule status, giving up\n");
+       }
+       ehci->ASS_poll_count = 0;
+
+       /* The status is up-to-date; restart or stop the schedule as needed */
+       if (want == 0) {        /* Stopped */
+               if (ehci->async_count > 0)
+                       ehci_set_command_bit(ehci, CMD_ASE);
+
+       } else {                /* Running */
+               if (ehci->async_count == 0) {
+
+                       /* Turn off the schedule after a while */
+                       ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_ASYNC,
+                                       true);
+               }
+       }
+}
+
+/* Turn off the async schedule after a brief delay */
+static void ehci_disable_ASE(struct ehci_hcd *ehci)
+{
+       ehci_clear_command_bit(ehci, CMD_ASE);
+}
+
+
 /* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
 static void ehci_poll_PSS(struct ehci_hcd *ehci)
 {
@@ -151,8 +198,10 @@ static void ehci_disable_PSE(struct ehci_hcd *ehci)
  * enum ehci_hrtimer_event in ehci.h.
  */
 static void (*event_handlers[])(struct ehci_hcd *) = {
+       ehci_poll_ASS,                  /* EHCI_HRTIMER_POLL_ASS */
        ehci_poll_PSS,                  /* EHCI_HRTIMER_POLL_PSS */
        ehci_disable_PSE,               /* EHCI_HRTIMER_DISABLE_PERIODIC */
+       ehci_disable_ASE,               /* EHCI_HRTIMER_DISABLE_ASYNC */
 };
 
 static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)