On Mon, Aug 21, 2000 at 03:58:46PM -0700, Dunlap, Randy wrote:
> > From: Greg KH [mailto:greg@wirex.com]
> >
> > > o usbpl_{read,write}(): on UP concurrent read/write
> > > operations could corrupt the urb structures if
> > > copy_to_user sleeps, on SMP it's worse.
> >
> > Again, what does this refer to? What functions, and in what
> > files? There
> > is no usbpl_ functions and I can't find any past references to them.
> > Does anyone know what this means?
>
> Could these be usblp_{read,write}() instead? (in usb/printer.c)
>
> Not that that helps me understand the problem...
Actually that does make more sense. And yes, this could be a problem.
But if we are going to call out every SMP problem in the USB drivers, we
would have a long list :)
David Brownell's recent patch for the dc2xx driver shows what needs to
be done to the drivers that don't have mechanisms to protect their
internal data structures and urbs from reentrancy. Do you want me to go
through the driver code to get a feel of which drivers have problems?
Hopefully I get a SMP box soon...
greg k-h
-- greg@(kroah|wirex).com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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