On Fri, 15 Apr 2005, David Brownell wrote: > > > > Auditing locking in all drivers is not. > > > > Switching to tasklets would result in revisting locking in drivers. > > > > > > Why would switching uhci-hcd over to a tasklet require any change in > > > other > > > drivers? > > > > You have to audit all drivers to check them for synchronization between > > the callback and other hard irqs. In addition to reap the full benefit from > > a switch to tasklets, you'd have to change the drivers to use > > spin_lock_bh(). > > Not many USB device driver use tasklets, but all those would need to be > audited/modified.
I hate to spoil all the speculation the two of you have been doing about this, but you're both wrong. Nothing would change. Even though the callbacks would be made from a tasklet instead of an interrupt handler they would continue to be made with interrupts disabled. And you couldn't change drivers to use spin_lock_bh() because other HCDs still don't use bottom halves. Alan Stern ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
