On Tue, Apr 20, 2004, Alan Stern <[EMAIL PROTECTED]> wrote: > On Tue, 20 Apr 2004, Johannes Erdfelt wrote: > > > On Tue, Apr 20, 2004, Alan Stern <[EMAIL PROTECTED]> wrote: > > > Those are things that will be doable in the future. For now it looks > > > best simply to ignore the flag and always interrupt, which is what the > > > patch does. > > > > I agree. It would be nice to have the UHCI driver prevent a worst case > > scenario of eating up lots of memory, but that kind of logic would be > > pretty complicated. > > > > Perhaps this patch should fix the comment to explain this is intended to > > be a temporary fix with a better performing solution to come later? > > I don't think it's worth going to the trouble. In fact this patch is a > reversion -- I only added support for the flag about a month ago (search > for "as233" in the message subject) and then changed my mind some time > later.
Ahh. I didn't remember adding it myself, so I was a little confused myself :) > Ultimately I am going to do something like what David outlined: a single > QH for each device+endpoint combination, not for each URB, with TDs > allocated in a just-in-time fashion (although I think the window will be > larger than 10 ms). Once all that is in place, adding limited support for > URB_NO_INTERRUPT will be easy. However, doing all that will be such a > major change to the driver that it probably shouldn't be attempted until > 2.7 starts up. Be careful. You can't modify certain values of the QH while it's on the schedule safely. Georg and I had a conversation about this a while ago which ended up in some changes to uhci.o since he had some very good points. That's why the driver uses a QH per URB, since it was the only safe, and efficient, way of doing it. Although, a just in time allocation scheme might be a good idea. That should be doable. JE ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
