Re: [linux-usb-devel] [PATCH] Ohci-hcd: fix endless loop (second take)

From: David Brownell
Date: Sat Nov 27 2004 - 01:31:42 EST


On Friday 26 November 2004 09:37, Colin Leroy wrote:
> On 26 Nov 2004 at 09h11, David Brownell wrote:
> > This isn't a good patch either... maybe your best
> > bet would be to find out why the IRQs stopped getting
> > delivered.
>
> It's probably a linux-wlan-ng issue...

I suspect PPC resume issues myself.


> What do you think
> of these logs ?
>
> #resume logs...
> #disconnecting the stick:
> usb 4-1: USB disconnect, address 2
> ohci_hcd 0001:10:1b.1: IRQ INTR_SF lossage

That does seem to be the first problem; fixing
it (that is, making sure IRQs arrive again!)
should make the rest go away.


> hfa384x_usbin_callback: Fatal, failed to resubmit rx_urb. error=-19
> hfa384x_dorrid: ctlx failure=REQ_TIMEOUT
> prism2sta_mlmerequest: Failed to read eth1 statistics: error=-5

Those look like plausible ways for that driver to
behave. "-19" == "-ENODEV" for device-gone (you
unplugged it!), though the rest (timeout, EIO)
suggest that WLAN code fault recovery is wierd.


> #reconnecting the stick:
> usb 4-1: new full speed USB device using address 3
> usb 4-1: control timeout on ep0out

As expected, if IRQs aren't arriving. Though you
may not be using the latest kernel; it's supposed
to give warnings about IRQ delivery problems after
resume too, not just on initial startup.


> maybe the lwlan driver should catch these and kill the urbs or
> something?

The only obvious "looks wrong" thing from that WLAN
code is discarding the non-recoverable ENODEV status
in favor of reporting a usually-recoverable (timeout)
then maybe-recoverable (EIO) error. But that's not
necessarily troublesome here.


> Thanks for your help, I'm not an expert at all in the usb world...

Most people aren't... :)

I'm not expert in PPC IRQ delivery, which is where the
root cause of this problem seems to live. We all have
places where we need help!

- Dave

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