Re: [PATCH 2/4] MFD: intel_pmt: Remove OOBMSM device

From: Lee Jones <lee.jones@linaro.org>
To: "David E. Box" <david.e.box@linux.intel.com>
Cc: hdegoede@redhat.com, mgross@linux.intel.com, bhelgaas@google.com,
	linux-kernel@vger.kernel.org,
	platform-driver-x86@vger.kernel.org, linux-pci@vger.kernel.org,
	Andy Shevchenko <andy.shevchenko@gmail.com>
Subject: Re: [PATCH 2/4] MFD: intel_pmt: Remove OOBMSM device
Date: Thu, 1 Jul 2021 09:01:33 +0100	[thread overview]
Message-ID: <YN12Xe0EZDdjDIrK@dell> (raw)
In-Reply-To: <f590ee871d0527a12b307f1494cb4c8a91c5e3c2.camel@linux.intel.com>

On Wed, 30 Jun 2021, David E. Box wrote:

> On Wed, 2021-06-30 at 11:15 +0100, Lee Jones wrote:
> > On Thu, 17 Jun 2021, David E. Box wrote:
> > 
> > > Unlike the other devices in intel_pmt, the Out of Band Management
> > > Services
> > > Module (OOBMSM) is actually not a PMT dedicated device. It can also
> > > be used
> > > to describe non-PMT capabilities. Like PMT, these capabilities are
> > > also
> > > enumerated using PCIe Vendor Specific registers in config space. In
> > > order
> > > to better support these devices without the confusion of a
> > > dependency on
> > > MFD_INTEL_PMT, remove the OOBMSM device from intel_pmt so that it
> > > can be
> > > later placed in its own driver. Since much of the same code will be
> > > used by
> > > intel_pmt and the new driver, create a new file with symbols to be
> > > used by
> > > both.
> > > 
> > > While performing this split we need to also handle the creation of
> > > platform
> > > devices for the non-PMT capabilities. Currently PMT devices are
> > > named by
> > > their capability (e.g. pmt_telemetry). Instead, generically name
> > > them by
> > > their capability ID (e.g. intel_extnd_cap_2). This allows the IDs
> > > to be
> > > created automatically.  However, to ensure that unsupported devices
> > > aren't
> > > created, use an allow list to specify supported capabilities.
> > > 
> > > Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> > > ---
> > >  MAINTAINERS                                |   1 +
> > >  drivers/mfd/Kconfig                        |   4 +
> > >  drivers/mfd/Makefile                       |   1 +
> > >  drivers/mfd/intel_extended_caps.c          | 208
> > > +++++++++++++++++++++
> > 
> > Please consider moving this <whatever this is> out to either
> > drivers/pci or drivers/platform/x86.
> 
> None of the cell drivers are in MFD, only the PCI drivers from which
> the cells are created. I understood that these should be in MFD. But
> moving it to drivers/platform/x86 would be fine with me. That keeps the
> code together in the same subsystem. Comment from Hans or Andy? 

You don't need to move everything there.  If a driver uses the MFD API
(like intel_pmt.c does), it can stay.  But all of this PCI/hardware/
platform specific capability craziness has no place here AFAICT.

> > I suggest Andy should also be on Cc.
> > 
> > >  drivers/mfd/intel_extended_caps.h          |  40 ++++
> > >  drivers/mfd/intel_pmt.c                    | 198 ++---------------
> > > ---
> > >  drivers/platform/x86/intel_pmt_crashlog.c  |   2 +-
> > >  drivers/platform/x86/intel_pmt_telemetry.c |   2 +-
> > >  8 files changed, 270 insertions(+), 186 deletions(-)
> > >  create mode 100644 drivers/mfd/intel_extended_caps.c
> > >  create mode 100644 drivers/mfd/intel_extended_caps.h
> > 
> 
> 

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