On Thursday 21 May 2009, Alan Stern wrote: > Dave: > > ehci_iso_stream->rescheduled and ->start seem never to get used. In > fact I can't even tell what ->rescheduled is supposed to count, since > it doesn't get incremented. Should they be removed? I guess so. Might be worth finding what removed setting ->rescheduled, since I know that message used to appear sometimes (when rude things happened). > The BUG_ON that's commented out of itd_patch() can actually be > triggered if somebody submits an URB with a sufficiently discontiguous > list of packet offsets. Discontiguous packet offsets sound kind of rude. :) > Without the BUG_ON, the result is memory > corruption. There's a comment about the offsets being strictly > increasing, but that's not enough to prevent the bug. What's that bug? > Neither > requirement is documented, so what should we do about this? I'd have to dive into that code again ... ISTR "cross" would be set on ITDs where a packet went from one page to the next, the model being that the ITD would only ever use a contiguous chunk of memory. There are hardware requirements on packet layout in the ITDs, but I don't recall noticing any conflicts between those and the software. > Alan Stern > > P.S.: I have a series of patches to clean up the Clear-TT-Buffer stuff. > The buffer is cleared after any problem (as required by the USB spec), > not just those that leave a CSPLIT pending. Any objection? No. -- 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
