On Mon, 1 Apr 2019, Suwan Kim wrote: > Patch "USB: HCD: support giveback of URB in tasklet context"[1] > introduced giveback of urb in tasklet context. [1] This patch was > applied to ehci but not xhci. [2] This patch significantly reduces > the hard irq time of xhci. Especially for uvc driver, the hard irq > including the uvc completion function runs quite long but applying > this patch reduces the hard irq time of xhci. Please read the kerneldoc for usb_submit_urb() and usb_kill_urb(), in particular, the parts that describe how isochronous URBs are treated. Can you guarantee that with this patch applied, xhci-hcd will continue to work as the kerneldoc describes? Alan Stern
