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| author | Alan Stern | 2012-07-11 17:22:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2012-07-17 01:54:25 +0200 |
| commit | bf6387bcd16975ba8952b094f262a359d74e1c8a (patch) | |
| tree | ac578ff256a5cd972c5866525c65e44e4360974e /drivers/usb/host/ehci-timer.c | |
| parent | USB: EHCI: use hrtimer for interrupt QH unlink (diff) | |
| download | kernel-qcow2-linux-bf6387bcd16975ba8952b094f262a359d74e1c8a.tar.gz kernel-qcow2-linux-bf6387bcd16975ba8952b094f262a359d74e1c8a.tar.xz kernel-qcow2-linux-bf6387bcd16975ba8952b094f262a359d74e1c8a.zip | |
USB: EHCI: use hrtimer for controller death
This patch (as1578) adds an hrtimer event to handle the death of an
EHCI controller. When a controller dies, it doesn't necessarily stop
running right away. The new event polls at 1-ms intervals to see when
all activity has safely stopped. This replaces a busy-wait polling
loop in the current code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-timer.c')
| -rw-r--r-- | drivers/usb/host/ehci-timer.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c index bd8b591771b0..0c5326a8883c 100644 --- a/drivers/usb/host/ehci-timer.c +++ b/drivers/usb/host/ehci-timer.c @@ -69,6 +69,7 @@ static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit) static unsigned event_delays_ns[] = { 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_ASS */ 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_PSS */ + 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_DEAD */ 1125 * NSEC_PER_USEC, /* EHCI_HRTIMER_UNLINK_INTR */ 10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_PERIODIC */ 15 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_ASYNC */ @@ -193,6 +194,30 @@ static void ehci_disable_PSE(struct ehci_hcd *ehci) } +/* Poll the STS_HALT status bit; see when a dead controller stops */ +static void ehci_handle_controller_death(struct ehci_hcd *ehci) +{ + if (!(ehci_readl(ehci, &ehci->regs->status) & STS_HALT)) { + + /* Give up after a few milliseconds */ + if (ehci->died_poll_count++ < 5) { + /* Try again later */ + ehci_enable_event(ehci, EHCI_HRTIMER_POLL_DEAD, true); + return; + } + ehci_warn(ehci, "Waited too long for the controller to stop, giving up\n"); + } + + /* Clean up the mess */ + ehci->rh_state = EHCI_RH_HALTED; + ehci_writel(ehci, 0, &ehci->regs->configured_flag); + ehci_writel(ehci, 0, &ehci->regs->intr_enable); + ehci_work(ehci); + + /* Not in process context, so don't try to reset the controller */ +} + + /* Handle unlinked interrupt QHs once they are gone from the hardware */ static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci) { @@ -233,6 +258,7 @@ static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci) static void (*event_handlers[])(struct ehci_hcd *) = { ehci_poll_ASS, /* EHCI_HRTIMER_POLL_ASS */ ehci_poll_PSS, /* EHCI_HRTIMER_POLL_PSS */ + ehci_handle_controller_death, /* EHCI_HRTIMER_POLL_DEAD */ ehci_handle_intr_unlinks, /* EHCI_HRTIMER_UNLINK_INTR */ ehci_disable_PSE, /* EHCI_HRTIMER_DISABLE_PERIODIC */ ehci_disable_ASE, /* EHCI_HRTIMER_DISABLE_ASYNC */ |