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authorAlan Stern <stern@rowland.harvard.edu>2013-01-25 17:17:43 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-25 15:06:01 -0800
commitee74290b7853db9d5fd64db70e5c175241c59fba (patch)
tree87662d59dcf312f8d8726a0999665e0e81bf3790
parent840008bb5162f029d5bc05959c7f51a3e8f9e0ff (diff)
USB: EHCI: fix timer bug affecting port resume
This patch (as1652) fixes a long-standing bug in ehci-hcd. The driver relies on status polls to know when to stop port-resume signalling. It uses the root-hub status timer to schedule these status polls. But when the driver for the root hub is resumed, the timer is rescheduled to go off immediately -- before the port is ready. When this happens the timer does not get re-enabled, which prevents the port resume from finishing until some other event occurs. The symptom is that when a new device is plugged in, it doesn't get recognized or enumerated until lsusb is run or something else happens. The solution is to re-enable the root-hub status timer after every status poll while a port resume is in progress. This bug hasn't surfaced before now because we never used to try to suspend the root hub in the middle of a port resume (except by coincidence). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Norbert Preining <preining@logic.at> Tested-by: Ming Lei <ming.lei@canonical.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/host/ehci-hub.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index f88be801d60..4d3b294f203 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -649,7 +649,11 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
status = STS_PCD;
}
}
- /* FIXME autosuspend idle root hubs */
+
+ /* If a resume is in progress, make sure it can finish */
+ if (ehci->resuming_ports)
+ mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(25));
+
spin_unlock_irqrestore (&ehci->lock, flags);
return status ? retval : 0;
}