[PATCH] USB root hub polling and suspend

[PATCH] USB root hub polling and suspend

[Paul Mackerras]

Currently with 2.5, when I suspend and resume my powerbook, I find
that the USB subsystem no longer sees root hub events, i.e. it doesn't
notice when I plug in a new USB device (it doesn't notice when I
unplug a device either but of course the driver for the device sees
that it is no longer responding).

It turns out that what happens is that the root hub timer goes off
after the OHCI driver has done its suspend stuff.  The timer routine
sees that the HCD is not running at the moment and doesn't schedule
another timeout.  Hence the series of timeouts stops.

The patch below fixes the problem for me.  Comments welcome.

Paul.

diff -urN linuxppc-2.5/drivers/usb/core/hcd.c pmac-2.5/drivers/usb/core/hcd.c
--- linuxppc-2.5/drivers/usb/core/hcd.c	Sun Jul 21 12:58:49 2002
+++ pmac-2.5/drivers/usb/core/hcd.c	Tue Jul 23 22:21:25 2002
@@ -454,7 +454,6 @@
 	/* rh_timer protected by hcd_data_lock */
 	if (timer_pending (&hcd->rh_timer)
 			|| urb->status != -EINPROGRESS
-			|| !HCD_IS_RUNNING (hcd->state)
 			|| urb->transfer_buffer_length < len) {
 		dbg ("not queuing status urb, stat %d", urb->status);
 		return -EINVAL;
@@ -508,8 +507,12 @@
 				BUG ();
 			}
 			spin_unlock_irqrestore (&hcd_data_lock, flags);
-		} else
+		} else {
 			spin_unlock_irqrestore (&urb->lock, flags);
+			spin_lock_irqsave (&hcd_data_lock, flags);
+			rh_status_urb (hcd, urb);
+			spin_unlock_irqrestore (&hcd_data_lock, flags);
+		}
 	} else {
 		/* this urb's been unlinked */
 		urb->hcpriv = 0;

Re: [PATCH] USB root hub polling and suspend

[Greg KH]

On Wed, Aug 07, 2002 at 08:51:14AM +1000, Paul Mackerras wrote:
> Currently with 2.5, when I suspend and resume my powerbook, I find
> that the USB subsystem no longer sees root hub events, i.e. it doesn't
> notice when I plug in a new USB device (it doesn't notice when I
> unplug a device either but of course the driver for the device sees
> that it is no longer responding).
> 
> It turns out that what happens is that the root hub timer goes off
> after the OHCI driver has done its suspend stuff.  The timer routine
> sees that the HCD is not running at the moment and doesn't schedule
> another timeout.  Hence the series of timeouts stops.
> 
> The patch below fixes the problem for me.  Comments welcome.

Thanks, I've added it to my tree and will send it on to Linus.

greg k-h