> From: yuanlinyu > Sent: Thursday, March 14, 2024 4:14 PM > To: 'Oliver Neukum' <oneukum@xxxxxxxx>; Alan Stern > <stern@xxxxxxxxxxxxxxxxxxx>; Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx > Subject: RE: [PATCH v1] usb: f_mass_storage: reduce chance to queue disable ep > > > From: Oliver Neukum <oneukum@xxxxxxxx> > > Sent: Thursday, March 14, 2024 3:54 PM > > > > > > Sorry, now for the longer explanation. You'd introduce a deadlock. > > You just cannot sleep with a spinlock held. It seems to me that > > I didn't review usb_ep_queue() clearly, in my test, I didn't hit sleep. > But the concern is good, will find better way to avoid it. Oliver, could you share one example which can sleep ? I check several UDC drivers, like dwc3, cdnsp, cdns3, Both disable/queue function have spinlock, this means no sleep, right ? > > > if you want to do this cleanly, you need to revisit the locking > > to use locks you can sleep under. > > > > HTH > > Oliver
