From: Alan Stern Date: Fri, 25 Jan 2013 22:17:43 +0000 (-0500) Subject: USB: EHCI: fix timer bug affecting port resume X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ee74290b7853db9d5fd64db70e5c175241c59fba;p=linux-beck.git 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 Reported-and-tested-by: Norbert Preining Tested-by: Ming Lei Cc: stable Signed-off-by: Greg Kroah-Hartman --- 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; }