On Wed, Apr 13, 2011 at 10:43:37AM -0400, Alan Stern wrote: > On Tue, 12 Apr 2011, Dmitry Torokhov wrote: > > > Currently, when resetting a device, xHCI driver disables all but one > > endpoints and frees their rings, but leaves alone any streams that > > might have been allocated. Later, when users try to free allocated > > streams, we oops in xhci_setup_no_streams_ep_input_ctx() because > > ep->ring is NULL. > > > > Let's free not only rings but also stream data as well, so that > > calling free_streams() on a device that was reset will be safe. > > What happens when the driver that allocated the streams initially wants > to use them after the reset? Is this driver supposed to be responsible > for re-allocating the streams in its post_reset method? Yes, I think so. It needs to re-initialize/set up the device anyway. FWIW the driver that I had issue with (the only one that uses streams at the moment - UAS) did not want to use them after reset. It was just trying to unbind from the device in otrderly fashion and was blowing up spectacularly. > > Wouldn't it make more sense to keep the streams around or That could be an option if we were keeping the original rings around as well. My reasoning that if we blow away rings we should blow away streams too so that we are consistent. > automatically re-allocate them? And if we fail? Or can't allocate as much as there was before? We'd have to notify the driver somehow. Too messy IMO. Thanks. -- Dmitry -- 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
