On Wed, 28 Apr 2004 12:27:34 -0400 (EDT)
Alan Stern <[EMAIL PROTECTED]> wrote:

> > ---
> > Issue a READ_TOC CBW to bulk out pipe
> > 
> > Issue a GET_DESCRIPTOR to pipe 0 (a different thread does this,
> > presumably)
> > 
> > Try to read data for READ_TOC from bulk in pipe -- pipe stalls because 
> > there's no CD in the drive and therefore no TOC data
> > 
> > Try to issue a CLEAR_FEATURE to clear the stall to pipe 0 -- this fails 
> > because there's already an URB in progress to pipe 0
> > 
> > USB driver then tries to read the CSW (never mind that the stall wasn't 
> > cleared)--this also fails because pipe is stalled
> > 
> > Try to issue a CLEAR_FEATURE again, with similar results

> Under Linux 2.4, one way to handle this is by preventing the other thread
> from issuing the GET_DESCRIPTOR to pipe 0 while the CDROM drive is busy.  
> You could find out what that other thread is and suspend or kill it.
> 
> Under Linux 2.6 there shouldn't be any problem.

Alan, I'm not up to speed. What code, exactly, does accomplish the
necessary serialization in 2.6? Can you give me a function name
and a lock or counter name?

Thanks,
-- Pete


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