Re: [PATCH AUTOSEL 5.8 55/62] RDMA/efa: Add EFA 0xefa1 PCI ID

[Sasha Levin]

On Fri, Aug 21, 2020 at 05:19:52PM -0300, Jason Gunthorpe wrote:
> On Fri, Aug 21, 2020 at 03:53:22PM -0400, Sasha Levin wrote:
> > On Fri, Aug 21, 2020 at 04:40:36PM -0300, Jason Gunthorpe wrote:
> > > On Fri, Aug 21, 2020 at 12:14:16PM -0400, Sasha Levin wrote:
> > > > From: Gal Pressman <galpress@xxxxxxxxxx>
> > > >
> > > > [ Upstream commit d4f9cb5c5b224dca3ff752c1bb854250bf114944 ]
> > > >
> > > > Add support for 0xefa1 devices.
> > > >
> > > > Link: https://lore.kernel.org/r/20200722140312.3651-5-galpress@xxxxxxxxxx
> > > > Reviewed-by: Shadi Ammouri <sammouri@xxxxxxxxxx>
> > > > Reviewed-by: Yossi Leybovich <sleybo@xxxxxxxxxx>
> > > > Signed-off-by: Gal Pressman <galpress@xxxxxxxxxx>
> > > > Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> > > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > > >  drivers/infiniband/hw/efa/efa_main.c | 6 ++++--
> > > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > Wait, what? Why is this being autosel'd?
> >
> > Stable trees try to pick up device enablement patches (such as patches
> > that add PCI IDs). I suppose that AUTOSEL get pretty eager to grab
> > those.
>
> Is it so common that old drivers will work with new HW with just a
> PCI_ID update?
>
> I would have guessed that is the minority situation

So keep in mind that a lot of it is not brand new HW, but rather same
HW repackaged by a different vendor, or HW that received minor tweaks
but where the old driver still works.

I suppose it's more common in the USB ID world these days, so I guess
I'll give PCI IDs a closer look next time.

--
Thanks,
Sasha