Re: [PATCH v2 2/2] cxl: add support for cxl reset

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Feb 21, 2025 at 11:45:56AM +0100, Lukas Wunner wrote:
> On Thu, Feb 20, 2025 at 08:39:06PM -0800, Srirangan Madhavan wrote:
> > Type 2 devices are being introduced and will require finer-grained
> > reset mechanisms beyond bus-wide reset methods.
> > 
> > Add support for CXL reset per CXL v3.2 Section 9.6/9.7
> > 
> > Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
> > ---
> >  drivers/pci/pci.c   | 146 ++++++++++++++++++++++++++++++++++++++++++++
> 
> drivers/pci/pci.c is basically a catch-all for anything that doesn't fit
> in one of the other .c files in drivers/pci.  I'm slightly worried that
> this (otherwise legitimate) patch increases the clutter in pci.c further,
> rendering it unmaintainable in the long term.

+1  The reset-related content in drivers/pci/pci.c has been growing
recently.  Maybe we should consider moving it all to a reset.c file.

> At the very least, I'm wondering if this can be #ifdef'ed to
> CONFIG_CXL_PCI?
> 
> One idea would be to move this newly added reset method, as well as the
> existing cxl_reset_bus_function(), to a new drivers/pci/cxl.c file.
> 
> I guess moving it to drivers/cxl/ isn't an option because cxl can be
> modular.
> 
> Another idea would be to move all the reset handling (which makes up
> a significant portion of pci.c) to a separate drivers/pci/reset.c.
> This might be beyond the scope of your patch, but in the interim,
> maybe at least an #ifdef can be added because the PCI core is also
> used e.g. on memory-constrained wifi routers which don't care about
> CXL at all.

Agree, we'll need some way to make this optional.

Bjorn