RE: [PATCH v3 01/10] Add auxiliary bus support

Parav Pandit
2020-11-05T20:37:22Z

> From: Dan Williams <dan.j.williams@intel.com>
> Sent: Friday, November 6, 2020 1:56 AM
>
> On Thu, Nov 5, 2020 at 11:40 AM Parav Pandit <parav@nvidia.com> wrote:
> >
> >
> >
> > > From: Ertman, David M <david.m.ertman@intel.com>
> > > Sent: Friday, November 6, 2020 12:58 AM
> > > Subject: RE: [PATCH v3 01/10] Add auxiliary bus support
> > >
> > > > -----Original Message-----
> > > > From: Dan Williams <dan.j.williams@intel.com>
> > > > Sent: Thursday, November 5, 2020 1:19 AM
> > > >
> >
> > [..]
> > > > > +
> > > > > +Another use case is for the PCI device to be split out into
> > > > > +multiple sub functions. For each sub function an
> > > > > +auxiliary_device will be created. A PCI sub function driver
> > > > > +will bind to such devices that will create its own one or more
> > > > > +class devices. A PCI sub function auxiliary device will likely
> > > > > +be contained in a struct with additional attributes such as
> > > > > +user defined sub function number and optional attributes such
> > > > > +as resources and a link to
> > > > the
> > > > > +parent device. These attributes could be used by systemd/udev;
> > > > > +and
> > > > hence should
> > > > > +be initialized before a driver binds to an auxiliary_device.
> > > >
> > > > This does not read like an explicit example like the previous 2.
> > > > Did you have something specific in mind?
> > > >
> > >
> > > This was added by request of Parav.
> > >
> > This example describes the mlx5 PCI subfunction use case.
> > I didn't follow your question about 'explicit example'.
> > What part is missing to identify it as explicit example?
>
> Specifically listing "mlx5" so if someone reading this document thinks to
> themselves "hey mlx5 sounds like my use case" they can go grep for that.
Ah, I see.
"mlx5" is not listed explicitly, because it is not included in this patchset.
In various previous discussions in this thread, mlx5 subfunction use case is described that justifies the existence of the bus.
I will be happy to update this documentation once mlx5 subfunction will be part of kernel so that grep actually shows valid output.
(waiting to post them as it uses auxiliary bus :-)).