On Sun, 18 Aug 2013, Ming Lei wrote: > > As far as I can see, these don't need to disable interrupts. All they > > protect against is the code in usb_sg_wait() and usb_sg_cancel(), which > > both run in process context. > > Yes. > > > But will lockdep complain if they don't disable interrupts? > > Looks lockdep won't complain because the lock can't be held in > another hardirq context.
Don't be so sure. Suppose you have two mass-storage devices, one connected by EHCI and one connected by UHCI. The one using UHCI _will_ invoke the completion handler in hardirq context, because uhci-hcd doesn't support tasklets. Have you tested this? > As I mentioned in 00/50, the patchset is basically a mechanical > change, so one patch can be dropped if anyone reviews and > concludes it isn't needed. I'm afraid that it might be needed to keep lockdep happy, not to prevent real problems. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
