I don't think this works. As I understand it, ep_ring->cycle_state contains the current cycle state at the enqueue pointer, not the dequeue pointer (it gets updated in inc_enq() but not in inc_deq() for transfer rings). That's the only reason we need to pull it out of the Endpoint Context at all... because we have long since overwritten our own software copy, when we originally enqueued the TD (and an arbitrary amount of further ones after it).
I think if we really want to play it safe, any solution for this must keep track of and only stop searching after both passing last_trb and reaching hw_dequeue (taking the cycle_state off the latter), since there might be cases where either of them could be more than one TRB after the other. Maybe if you add another last_found variable and depend the loop on both you could implement that in a clear way? (Also, I'm wondering if we should just drop the code that skips whole segments to make it simpler, since I can hardly think of any real-world examples where a single TD would cover a whole segment.) -- 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
