Re: [PATCH] usb ehci_iaa_watchdog fix

[Mark Lord <lkml@rtr.ca>]

Alan Stern wrote:
> On Wed, 2 Apr 2008, Mark Lord wrote:
> 
>> Yup, that does indeed cure it.
>> Here's a patch, in case you didn't already generate one:
>>
>> Signed-off-by: Mark Lord <mlord@pobox.com>
>>
>> --- rc8/drivers/usb/host/ehci-hcd.c	2008-03-11 11:18:40.000000000 -0400
>> +++ linux/drivers/usb/host/ehci-hcd.c	2008-04-02 12:16:40.000000000 -0400
>> @@ -289,9 +289,7 @@
>>  	 * (a) SMP races against real IAA firing and retriggering, and
>>  	 * (b) clean HC shutdown, when IAA watchdog was pending.
>>  	 */
>> -	if (ehci->reclaim
>> -			&& !timer_pending(&ehci->iaa_watchdog)
>> -			&& HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
>> +	if (ehci->reclaim && !timer_pending(&ehci->iaa_watchdog)) {
>>  		u32 cmd, status;
>>  
>>  		/* If we get here, IAA is *REALLY* late.  It's barely
> 
> Okay, I'm puzzled.  How could this make any difference?  
> ehci_bus_suspend() calls end_unlink_async() anyway, whenever reclaim is 
> set.
> 
> Is the real problem that it does so before calling ehci_work() instead 
> of after calling ehci_halt()?
> 
> Mark, if you want to experiment some more, try reverting your patch 
> above and moving:
..

Here's what I did, and yes, this also works.  Pick one.

This patch, suggested by Alan Stern, fixes the hung USB issues
on my notebook from suspend/resume cycles.

Signed-off-by: Mark Lord <mlord@pobox.com>

--- rc8/drivers/usb/host/ehci-hub.c	2008-03-11 11:18:40.000000000 -0400
+++ linux/drivers/usb/host/ehci-hub.c	2008-04-02 13:28:50.000000000 -0400
@@ -135,8 +135,6 @@
 		hcd->state = HC_STATE_QUIESCING;
 	}
 	ehci->command = ehci_readl(ehci, &ehci->regs->command);
-	if (ehci->reclaim)
-		end_unlink_async(ehci);
 	ehci_work(ehci);
 
 	/* Unlike other USB host controller types, EHCI doesn't have
@@ -180,6 +178,9 @@
 	ehci_halt (ehci);
 	hcd->state = HC_STATE_SUSPENDED;
 
+	if (ehci->reclaim)
+		end_unlink_async(ehci);
+
 	/* allow remote wakeup */
 	mask = INTR_MASK;
 	if (!device_may_wakeup(&hcd->self.root_hub->dev))