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| author | Alan Stern <stern@rowland.harvard.edu> | 2013-01-25 17:17:43 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-25 15:06:01 -0800 |
| commit | ee74290b7853db9d5fd64db70e5c175241c59fba (patch) | |
| tree | 87662d59dcf312f8d8726a0999665e0e81bf3790 /drivers | |
| parent | 840008bb5162f029d5bc05959c7f51a3e8f9e0ff (diff) | |
| download | linux-ee74290b7853db9d5fd64db70e5c175241c59fba.tar.gz linux-ee74290b7853db9d5fd64db70e5c175241c59fba.tar.bz2 linux-ee74290b7853db9d5fd64db70e5c175241c59fba.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index f88be801d60c..4d3b294f203e 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; } |