Messages in this thread | | | Date | Mon, 21 Aug 2000 16:30:04 -0700 | From | Greg KH <> | Subject | Re: Updated Linux 2.4 issues page |
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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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