Re: [REGRESSION] "USB: use kfifo to buffer usb-generic serial writes" causes gobi_loader to hang

From: Anssi Hannula
Date: Sun Feb 21 2010 - 16:42:19 EST


On sunnuntai 21 helmikuu 2010 23:28:54 Alan Stern wrote:
> On Sat, 20 Feb 2010, Oliver Neukum wrote:
> > Am Samstag, 20. Februar 2010 17:03:41 schrieb Anssi Hannula:
> > > > Can load usbserial with "debug=1"?
> > >
> > > Here's the end of dmesg when running with that option:
> > > http://stuff.onse.fi/gobi2000/gobi-regression.dmesg.log
> > >
> > > This is again with the gobi_loader with extra sleep added in the
> > > beginning. Otherwise it hangs (which is the actual original problem).
> >
> > That log makes sure that the final cancellation comes from closing
> > the file. Is that a log of a working run?
>
> Could this simply be one of those cases where the device file is closed
> just after the final write URB is submitted but before it can complete,
> so the URB gets cancelled and the data isn't transferred?

Seems so. I don't think that is the expected behaviour though (and of course
it used to work).

And of course this doesn't explain why it hangs (and the WARNING) if I remove
the sleep calls I added in gobi_loader.

--
Anssi Hannula
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