From 314466101c6ae14f6f5db8a86eda1509ba2c02a8 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 11 Jul 2012 11:22:21 -0400 Subject: USB: EHCI: use hrtimer for async schedule This patch (as1576) adds hrtimer support for managing ehci-hcd's async schedule. Just as with the earlier change to the periodic schedule management, two new hrtimer events take care of everything. One event polls at 1-ms intervals to see when the Asynchronous Schedule Status (ASS) flag matches the Asynchronous Schedule Enable (ASE) value; the schedule's state must not be changed until it does. The other event delays for 15 ms after the async schedule becomes empty before turning it off. The new events replace a busy-wait poll and a kernel timer usage. They also replace the rather illogical method currently used for indicating the async schedule should be turned off: attempting to unlink the dedicated QH at the head of the async list. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/usb/host/ehci.h') diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index da2e0ab23850..bf06bbb77ba4 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -79,8 +79,10 @@ enum ehci_rh_state { * ehci-timer.c) in parallel with this list. */ enum ehci_hrtimer_event { + EHCI_HRTIMER_POLL_ASS, /* Poll for async schedule off */ EHCI_HRTIMER_POLL_PSS, /* Poll for periodic schedule off */ EHCI_HRTIMER_DISABLE_PERIODIC, /* Wait to disable periodic sched */ + EHCI_HRTIMER_DISABLE_ASYNC, /* Wait to disable async sched */ EHCI_HRTIMER_NUM_EVENTS /* Must come last */ }; #define EHCI_HRTIMER_NO_EVENT 99 @@ -93,6 +95,7 @@ struct ehci_hcd { /* one per controller */ struct hrtimer hrtimer; int PSS_poll_count; + int ASS_poll_count; /* glue to PCI and HCD framework */ struct ehci_caps __iomem *caps; @@ -110,6 +113,7 @@ struct ehci_hcd { /* one per controller */ struct ehci_qh *async_unlink_last; struct ehci_qh *qh_scan_next; unsigned scanning : 1; + unsigned async_count; /* async activity count */ /* periodic schedule support */ #define DEFAULT_I_TDPS 1024 /* some HCs can do less */ @@ -229,7 +233,6 @@ static inline void iaa_watchdog_done(struct ehci_hcd *ehci) enum ehci_timer_action { TIMER_IO_WATCHDOG, TIMER_ASYNC_SHRINK, - TIMER_ASYNC_OFF, }; static inline void -- cgit v1.2.2