On Wed, 9 Sep 2015, Laurent Pinchart wrote: > On Wednesday 09 September 2015 10:30:12 Hans de Goede wrote: > > On 08-09-15 16:36, Alan Stern wrote: > > > On Tue, 8 Sep 2015, Hans de Goede wrote: > > >> On 09/07/2015 06:23 PM, Mian Yousaf Kaukab wrote: > > >>> urb completion callback is executed in host controllers interrupt > > >>> context. To keep preempt disable time short, add urbs to a list on > > >>> completion and schedule work to process the list. > > >>> > > >>> Moreover, save timestamp and sof number in the urb completion callback > > >>> to avoid any delays. > > >> > > >> Erm, I thought that we had already moved to using threaded interrupt > > >> handling for the urb completion a while (1-2 years ?) back. Is this then > > >> still needed ? > > > > > > We moved to handling URB completions in a tasklet, not a threaded > > > handler. > > > > Right. > > > > > (Similar idea, though.) And the change was made in only one > > > or two HCDs, not in all of them. > > > > Ah, I was under the impression this was a core change, not a per > > hcd change. > > Instead of fixing the issue in the uvcvideo driver, would it then make more > sense to fix it in the remaining hcd drivers ? Unfortunately that's not so easy. It involves some subtle changes related to the way isochronous endpoints are handled. I wouldn't know what to change in any of the HCDs, except the ones that I maintain. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
