diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2013-01-25 17:17:43 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-11 09:04:45 -0800 |
| commit | bf7937925cb086b9a5acb220fcd431506842c25e (patch) | |
| tree | dace1b0e197ecb350484602fb5b50f82cf3961b9 | |
| parent | d01875f11f05f76fc471cec94d701201c1b34389 (diff) | |
USB: EHCI: fix timer bug affecting port resume
commit ee74290b7853db9d5fd64db70e5c175241c59fba upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 914ce9370e70..b9f7f11bce9b 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -623,7 +623,11 @@ 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; } |