On Thu, 5 Dec 2019, Erkka Talvitie wrote: > I tested this change and the issue did not reproduce. > > However when I was writing the comments for the patch I started to think > what happens in this following scenario: > > The PID Code is IN. > > 1. First there will be XACT, the CERR is decremented, let's say from 3 to 2 > and the host controller executes a retry. > 2. On this next try there will happen the condition mentioned in the Table > 4-13 of the EHCI specification so that the MMF is set and the queue is > halted (because it is IN). > 3. To my understanding now the execution enters to this first stall check > if, as CERR is > 0 and CERR < EHCI_TUNE_CERR. > 4. The -EPIPE (stall) is returned when actually the queue was halted due to > MMF - not stall - and the -EPROTO should be returned. > > Is my logic correct or am I missing something? The same thought had occurred to me. > If you agree with me then I would like to present you a bit more bold (in a > sense of amount of refactoring) RFC. In high level this another RFC > separates 1. error check and 2. stall check. For me this approach is a bit > easier to understand from the code. Or then please propose another > solution. I was going to suggest: Just check for MMF and PID == IN before checking for STALL. Everything else can remain the way it is. Alan Stern
