Re: [PATCH v1 2/2] net: dsa: rtl8366rb: Quick fix to work with fw_devlink=on

[Saravana Kannan <saravanak@google.com>]

On Thu, Aug 26, 2021 at 4:29 AM Alvin Šipraga <ALSI@bang-olufsen.dk> wrote:
>
> Hi Saravana,
>
>  From looking at the code, the Marvell DSA driver mv88e6xxx may also
> suffer from the same problem if fw_devlink=on. Maybe somebody (Andrew?)
> could test so that you know whether include a simlar patch to that
> driver in your series.
>
> Other drivers may be effected too - as Andrew said in the other thread,
> this is not an uncommon pattern for DSA drivers.
>
> On 8/26/21 9:45 AM, Saravana Kannan wrote:
> > This is just a quick fix to make this driver work with fw_devlink=on.
> > The proper fix might need a significant amount of rework of the driver
> > of the framework to use a component device model.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> With the caveat that it's a test with my RFC rtl8365mb subdriver...
>
> Tested-by: Alvin Šipraga <alsi@bang-olufsen.dk>

Thanks for testing. And just to be sure we are all on the same page:
Without this patch the PHYs get handled by the Generic PHY driver.
With this patch, the PHYs are handled by their specific driver.
Correct?

-Saravana

>
> Kind regards,
> Alvin
>
> > ---
> >   drivers/net/dsa/realtek-smi-core.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
> > index 8e49d4f85d48..f79c174f4954 100644
> > --- a/drivers/net/dsa/realtek-smi-core.c
> > +++ b/drivers/net/dsa/realtek-smi-core.c
> > @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
> >       var = of_device_get_match_data(dev);
> >       np = dev->of_node;
> >
> > +     /* This driver assumes the child PHYs would be probed successfully
> > +      * before this functions returns. That's not a valid assumption, but
> > +      * let fw_devlink know so that this driver continues to function with
> > +      * fw_devlink=on.
> > +      */
> > +     np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
> > +
> >       smi = devm_kzalloc(dev, sizeof(*smi) + var->chip_data_sz, GFP_KERNEL);
> >       if (!smi)
> >               return -ENOMEM;
> >