On Friday 01 December 2006 20:43, Alfred Perlstein wrote: > * M. Warner Losh <[EMAIL PROTECTED]> [061201 11:30] wrote: > > Have you looked at the usb work that Hans Petter Selasky > > at http://www.turbocat.net/~hselasky/usb4bsd yet? > > I just did, while it solves a lock order problem, this doesn't > appear to solve the programmitic issues, namely multiple usb IOs > requiring callbacks and how to issue a series of complex usb > IOs from interrupt context. > > Basically, I need to be able to do USB IO as if I was doing normal > BUS IO, usb does not offer this in interrupt context except as a > series of callbacks that appear to be programmatically impossible > to implement.
Yes, yes, this is supported. See the USBD_USE_POLLING flag. > > Have a look at if_aue.c, then look at any of the error cases that > might be called from interrupt context, they wind up doing sync IO > to the device which is illegal (sleeping while holding a driver > lock). > > Hans Petter Selasky's work is nice, however it doesn't solve > these issues, the lock would still have to be held. You don't want to do things without holding a lock. > Do you understand that I'm trying to give usb ethernet the > same ease of programming that other devices on a "fast bus" > have? Yes, but that comes at an expense. Higher CPU usage, more delay. --HPS _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-smp To unsubscribe, send any mail to "[EMAIL PROTECTED]"
