On Wed, Nov 07, 2018 at 05:40:14PM -0800, Guenter Roeck wrote: > On 11/7/18 3:14 PM, Bjorn Helgaas wrote: > > > > > > > > There is no INT3401 on any newer atom or core platforms, so you can't > > > enumerate on this device. We don't control what ACPI device is present > > > on a system. It depends on what the other non-Linux OS is using. > > > > Sure, you can't *force* OEMs to supply a given ACPI device, but you > > can certainly say "if you want this functionality, supply INT3401 > > devices." That's what you do with PNP0A03 (PCI host bridges), for > > example. If an OEM doesn't supply PNP0A03 devices, the system can > > boot just fine as long as you don't need PCI. > > > > This model of using the PCI IDs forces OS vendors to release updates > > for every new platform. I guess you must have considered that and > > decided whatever benefit you're getting was worth the cost. > > > > I really dislike where this is going. Board vendors - and that included > Intel when Intel was still selling boards - have a long history of only > making mandatory methods available in ACPI. Pretty much all of them don't > make hardware monitoring information available via ACPI. This is a pain > especially for laptops where the information is provided by an embedded > controller. On systems with Super-IO chips with dedicated hardware > monitoring functionality, they often go as far as signing mutual NDAs > with chip vendors, which lets both the board and the chip vendor claim > that they can not provide chip specifications to third parties, aka > users. > > You are pretty much extending that to CPU temperature monitoring. The > fallout, if adopted, will be that it will effectively no longer be > possible to monitor the temperature on chips supporting this > "feature". > > I do not think that would be a good idea. I wasn't aware of these political implications. Thanks for raising them. I'm not in a position to balance those implications vs the technical question of minimizing the burden of supporting new platforms, so I'll try again to bow out of this. Bjorn
