On Sat, May 30, 2020 at 05:25:11PM +0200, Oliver Neukum wrote: > Am Donnerstag, den 28.05.2020, 16:58 -0400 schrieb Alan Stern: > > On Thu, May 28, 2020 at 09:51:35PM +0200, Andrey Konovalov wrote: > > > > > I don't understand what the problem is. Can you explain in more general > > > > terms -- nothing specific to wdm or anything like that -- what you are > > > > concerned about? Is this something that could happen to any gadget > > > > driver? Or any USB class device driver? Or does it only affect > > > > usespace components of raw-gadget drivers? > > > > > > So, AFAIU, we have a driver whose flush() callback blocks on > > > wait_event(), which can only terminate when either 1) the driver > > > receives a particular USB response from the device or 2) the device > > > disconnects. > > > > This sounds like a bug in the driver. What would it do if someone had a > > Arguably yes. I will introduce a timeout. Unfortunately flush() > requires a non-interruptible sleep, as you cannot sanely return EAGAIN. But maybe you can kill some URBs and drop some data. Alan Stern
