USB: EHCI: use hrtimer for interrupt QH unlink
This patch (as1577) adds hrtimer support for unlinking interrupt QHs
in ehci-hcd. The current code relies on a fixed delay of either 2 or
55 us, which is not always adequate and in any case is totally bogus.
Thanks to internal caching, the EHCI hardware may continue to access
an interrupt QH for more than a millisecond after it has been unlinked.
In fact, the EHCI spec doesn't say how long to wait before using an
unlinked interrupt QH. The patch sets the delay to 9 microframes
minimum, which ought to be adequate.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 25329e4..8aa740d 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -302,6 +302,7 @@
if (ehci->async_unlink)
end_unlink_async(ehci);
+ ehci_handle_intr_unlinks(ehci);
/* allow remote wakeup */
mask = INTR_MASK;