Hi Conor On Mon, 10 Jun 2024 at 08:32, Conor Dooley <conor.dooley@xxxxxxxxxxxxx> wrote: > > On Fri, Jun 07, 2024 at 06:55:01PM +0100, Conor Dooley wrote: > > On Fri, Jun 07, 2024 at 06:29:49PM +0100, Dave Stevenson wrote: > > > > > > > --- > > > > > I got the report of this third hand, I don't have a device and can't > > > > > test this. I do wonder why the RPis get away with the sequence that > > > > > seemingly doesn't work for the guy that reported this to me. My theory > > > > > is either that they noticed the sequence was wrong while adding some > > > > > other MSR access that is needed on this board while either cross > > > > > checking the values written or because the other MSR accesses didn't > > > > > take effect. > > > > > > Did the change fix it for the reporter? We're using the driver with no > > > changes to the register settings cf mainline. > > > Why it works on the Pi but not on a Microchip board is likely to be > > > something quite subtle. > > > > I've asked, maybe it turns out to just be the first of my suggestions, > > and they noticed it was not matching in passing. > > Apparently it was the latter & they did need to fix the sequence to be > able to write the MSRs. Fair enough. > > They did introduce two > > additional MSR accesses, both outside of the range documented in the > > datasheets I could find online. They did have explanations for what those > > undocumented MSRs did (0x5040 and 0x5041) in the mail I got, but given > > it's third hand info to me, I dunno if we have the datasheet etc. I'll > > try to find out some more next week. > > Seemingly what those two additional MSRs do is under NDA so I would have > no way of justifying a patch to add them or the devicetree property > required to know whether or not the additional MSR writes is needed. :) NDAs can be a real pain sometimes. I'm happy with the patch though, and it doesn't stop anything else working on the Pi. Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> Tested-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
