Re: [PATCH net-next v2 08/11] of: property: Add device link support for PCS

From: Saravana Kannan
Date: Tue Nov 08 2022 - 15:57:00 EST


On Mon, Nov 7, 2022 at 1:36 PM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Mon, Nov 7, 2022 at 2:50 PM Sean Anderson <sean.anderson@xxxxxxxx> wrote:
> >
> > On 11/7/22 15:22, Vladimir Oltean wrote:
> > > On Mon, Nov 07, 2022 at 02:10:10PM -0600, Rob Herring wrote:
> > >> On Thu, Nov 03, 2022 at 05:06:47PM -0400, Sean Anderson wrote:
> > >> > This adds device link support for PCS devices. Both the recommended
> > >> > pcs-handle and the deprecated pcsphy-handle properties are supported.
> > >> > This should provide better probe ordering.
> > >> >
> > >> > Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx>
> > >> > ---
> > >> >
> > >> > (no changes since v1)
> > >> >
> > >> > drivers/of/property.c | 4 ++++
> > >> > 1 file changed, 4 insertions(+)
> > >>
> > >> Seems like no dependency on the rest of the series, so I can take this
> > >> patch?
> > >
> > > Is fw_devlink well-behaved these days, so as to not break (forever defer)
> > > the probing of the device having the pcs-handle, if no driver probed on
> > > the referenced PCS? Because the latter is what will happen if no one
> > > picks up Sean's patches to probe PCS devices in the usual device model
> > > way, I think.
> >
> > Last time [1], Saravana suggested to move this to the end of the series to
> > avoid such problems. FWIW, I just tried booting a LS1046A with the
> > following patches applied
> >
> > 01/11 (compatibles) 05/11 (device) 08/11 (link) 09/11 (consumer)
> > =================== ============== ============ ================
> > Y N Y N
> > Y Y Y Y
> > Y Y Y N
> > N Y Y N
> > N N Y N
> >
> > and all interfaces probed each time. So maybe it is safe to pick
> > this patch.
>
> Maybe? Just take it with the rest of the series.
>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>

Let's have Vladimir ack this. I'm not sure if it's fully safe yet. I
haven't done the necessary fixes for phy-handle yet, but I don't know
how pcs-handle and pcsphy-handle are used or if none of their uses
will hit the chicken and egg problem that some uses of phy-handle hit.

-Saravana