Re: [PATCH v3 2/5] MFD: intel_pmt: Support non-PMT capabilities

From: Lee Jones
Date: Tue Sep 28 2021 - 03:54:52 EST

On Mon, 27 Sep 2021, David E. Box wrote:

> On Mon, 2021-09-27 at 19:36 +0200, Greg KH wrote:
> > On Wed, Sep 22, 2021 at 02:30:04PM -0700, David E. Box wrote:
> > > Intel Platform Monitoring Technology (PMT) support is indicated by presence
> > > of an Intel defined PCIe DVSEC structure with a PMT ID. However DVSEC
> > > structures may also be used by Intel to indicate support for other
> > > capabilities unrelated to PMT.  OOBMSM is a device that can have both PMT
> > > and non-PMT capabilities. In order to support these capabilities it is
> > > necessary to modify the intel_pmt driver to handle the creation of platform
> > > devices more generically.
> >
> > I said this on your other driver submission, but why are you turning a
> > PCIe device into a set of platform devices and craming it into the MFD
> > subsystem?
> >
> > PCIe devices are NOT platform devices.
> But they *are* used to create platform devices when the PCIe device is multi-functional, which is
> what intel_pmt is.
> >
> > Why not use the auxiliary bus for this thing if you have individual
> > drivers that need to "bind" to the different attributes that this single
> > PCIe device is exporting.
> It wasn't clear in the beginning how this would evolve. MFD made sense for the PMT (platform
> monitoring technology) driver. PMT has 3 related but individually enumerable devices on the same IP,
> like lpss. But the same IP is now being used for other features too like SDSi. We could work on
> converting this to the auxiliary bus and then covert the cell drivers.

I see this as subsequent work. It should not affect this submission.

FWIW, I still plan to review this set for inclusion into MFD.

Lee Jones [李琼斯]
Senior Technical Lead - Developer Services │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog