> -----Original Message----- > From: Andy Lutomirski [mailto:[email protected]] > Sent: Thursday, June 16, 2016 1:41 PM > To: Limonciello, Mario <[email protected]> > Cc: Greg Kroah-Hartman <[email protected]>; Andy Lutomirski > <[email protected]>; Mathias Nyman <[email protected]>; USB > list <[email protected]>; Mathias Nyman > <[email protected]>; Dominguez, Jared > <[email protected]> > Subject: Re: Minor xhci issues (failed to peer) on Dell XPS 13 9350 (Skylake) > > On Sun, Mar 13, 2016 at 7:29 PM, Mario Limonciello > <[email protected]> wrote: > > > > > > On 03/12/2016 02:33 PM, Andy Lutomirski wrote: > >> On Sat, Mar 12, 2016 at 11:35 AM, Andy Lutomirski <[email protected]> > wrote: > >> Got it. I was barking up the wrong tree. > >> > >> Q: What happens if _Q66 runs concurrently with itself: > >> > >> A: > >> > >> Method (_Q66, 0, NotSerialized) // _Qxx: EC Query > >> { > >> Acquire (PATM, 0x0064) > >> If ((ECRD != One)) > >> { > >> Return (Zero) > >> } > >> > >> NEVT () > >> Release (PATM) > >> Return (Zero) > >> } > >> > >> The first one acquires PATM. The second one fails to acquire PATM due > >> to the timeout, does something potentially harmful when it reenters > >> NEVT (not sure -- maybe it's fine), then blows up when it tries to > >> release PATM, which it doesn't hold. > >> > >> --Andy > > Andy, > > > > Our team has confirmed this mistake and will issue a fix in a future > > BIOS. For now if you want to build your own DSDT to see if this is > > causing your type-C problems the Release(PATM) will be inserted in the > > obvious location. > > > > FWIW this issue will affect many platforms in this generation. (XPS > > 9550, XPS 9350, Precision 5510, and more) > > > > FYI: the H_EC.CHRG issue seems to be fixed in 1.4.3. The PATM issue > is still there by inspection of the code, although I haven't gotten > unlucky enough to trigger it yet.
Thanks for the heads up. I'll poke the team and find out if it was pushed out, or it was a different fix than previously planned. If you trigger it and it's still leading to any problems let me know.
