On Mon, Oct 05, 2020 at 05:38:22PM -0600, Shuah Khan wrote: > On 10/5/20 9:25 AM, Alan Stern wrote: > > On Mon, Oct 05, 2020 at 05:21:30PM +0200, Andrey Konovalov wrote: > > No, no -- it won't work right if it's called in process context. Not > > only do the spinlock calls leave the interrupt flag unchanged, also the > > driver callback routines may expect to be invoked with interrupts > > disabled. (We have tried to fix this, but I'm not at all certain that > > all the cases have been updated.) > > > > In the case of vhci case, usb_hcd_giveback_urb() is called from vhci's > urb_enqueue, when it determines it doesn't need to xmit the urb and can give > it back. This path runs in task context. > > Do you have any recommendation on how this case can be handled? Just call local_irq_disable() before usb_hcd_giveback_urb(), and local_irq_enable() afterward. Alan Stern
