On Wed, Feb 12, 2020 at 02:41:04PM +0000, John Garry wrote: > On 12/02/2020 13:55, Sudeep Holla wrote: > > On Wed, Feb 12, 2020 at 12:48:33PM +0000, John Garry wrote: > > > On 12/02/2020 11:59, Sudeep Holla wrote: > > > > [...] > > > > Hi Sudeep, > > > > > Yes, as mentioned above. We are not going to do extra work for lazy firmware. > > > > > > I don't think it's reasonable to just label this as lazy. The table may just > > > not have the flag set unintentionally. FW and software guys make mistakes, > > > like the mistakes in PPTT, itself. > > > > > > > We are not talking about flags, it's UID and it is pretty important if > > there are more than one objects of same time. > > > > I am talking about the Processor ID valid flag, which is specifically > related. > Ah OK, sorry I had forgotten the specific. I recall it now. > > > > Linux also will be lazy on such platform and provide weird unique numbers > > > > like in the above case you have mentioned. > > > > > > Personally I think that the kernel can be do better than provide meaningless > > > values like this, since it knows the processor IDs and which physical > > > package they belong to. > > > > > > > This was discussed quite a lot, I can dig and point you to it. That's the > > reason for choosing offset. We are *not going back* to this again. Fix the > > firmware before it gets copied for all future platforms and Linux has to > > deal with that *forever*. > > I would liked to have been made aware earlier of the oversight. Quite often > we only find problems when someone or something complains. > Agreed. > It is a strange API to provide offsets like this, and I did not realize that > they were actually being exposed to userspace. > We couldn't come up with something that produces same result always and obtained from firmware data. Yes that being in the user-space was the main concern for not generating it in the Linux as we can't guarantee to generate same ID for a given physical socket. Depends on the order in which we boot them or something similar. > > > > > If not, at least make the user know of potential deficiencies in the table. > > > > > > > How ? What are your suggestions ? Does adding a warning or note that UID > > is missing and offset is chosen help ? > > I'd say so. I know now, but let's save others the potential hassle. And > having this debate again. > No argument there. I agree completely. > I am kind of fine with that. > > How about something like this: > Looks good to me. Please post the patch. I am not sure on Rafael's preference on such lengthy warnings(does it need to be split ?) -- Regards, Sudeep
