On Mon, 19 Jan 2009, David Brownell wrote: > > > 1. Drivers need to cope with any context and any locks held. > > > This seems to be hardly practical to me. We'd beg for bugs. > > > > It's the situation we're in right now. So far there haven't been very > > many bugs. > > Haven't been many reports mostly by chance. Mass storage > could hit similar issues after scatterlist cleanup, ISTR. No. The usb_sg_* routines are very careful to release the spinlock before calling usb_submit_urb or usb_unlink_urb. For example, sg_complete() contains this: /* the previous urbs, and this one, completed already. * unlink pending urbs so they won't rx/tx bad data. * careful: unlink can sometimes be synchronous... */ spin_unlock(&io->lock); ... Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
