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SubjectRe: Updated Linux 2.4 issues page
On Mon, Aug 21, 2000 at 04:13:00PM -0700, Dunlap, Randy wrote:
> usblp_read() and usblp_write() already use separate urbs
> for read vs. write and for each instance of the lp (minor).
> Can you give me a brief explanation of the problem?
> (and I'll look at David's dc2xx patch).

>From what I understand, copy_to_user can sleep, then (for the usblp_read
function) the read can be called again, the data can be written to the
urb and submitted, then the previous copy_to_user wakes up, and tries to
resubmit the urb again with different data this time. Not good.

Same thing for the usblp_write function.

I'll try to go through the drivers, and post a summary later tonight.

greg k-h

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