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authorAlan Stern <stern@rowland.harvard.edu>2012-07-11 11:23:04 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-16 16:56:47 -0700
commit18aafe64d75d0e27dae206cacf4171e4e485d285 (patch)
treeda5a4c0cb9bbc664c489be69956cd275ae5e0f6b /drivers/usb/host/ehci-sched.c
parent569b394f53f0abd177cc665c9b4ace89e3f4c7fb (diff)
downloadlinux-stericsson-18aafe64d75d0e27dae206cacf4171e4e485d285.tar.gz
USB: EHCI: use hrtimer for the I/O watchdog
This patch (as1586) replaces the kernel timer used by ehci-hcd as an I/O watchdog with an hrtimer event. Unlike in the current code, the watchdog event is now always enabled whenever any isochronous URBs are active. This will prevent bugs caused by the periodic schedule wrapping around with no completion interrupts; the watchdog handler is guaranteed to scan the isochronous transfers at least once during each iteration of the schedule. The extra overhead will be negligible: one timer interrupt every 100 ms. 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-sched.c')
-rw-r--r--drivers/usb/host/ehci-sched.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 263b542985c0..26ce8fef0e5b 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -489,6 +489,7 @@ static void enable_periodic(struct ehci_hcd *ehci)
/* Don't start the schedule until PSS is 0 */
ehci_poll_PSS(ehci);
+ turn_on_io_watchdog(ehci);
}
static void disable_periodic(struct ehci_hcd *ehci)
@@ -1649,7 +1650,6 @@ static void itd_link_urb(
iso_sched_free (stream, iso_sched);
urb->hcpriv = NULL;
- timer_action (ehci, TIMER_IO_WATCHDOG);
++ehci->isoc_count;
enable_periodic(ehci);
}
@@ -2052,7 +2052,6 @@ static void sitd_link_urb(
iso_sched_free (stream, sched);
urb->hcpriv = NULL;
- timer_action (ehci, TIMER_IO_WATCHDOG);
++ehci->isoc_count;
enable_periodic(ehci);
}