Re: [PATCH] tg3: Add param `short_preamble` to enable MDIO traffic to external PHYs

[Andrew Lunn]

On Fri, Aug 02, 2024 at 12:51:15PM -0700, Michael Chan wrote:
> On Fri, Aug 2, 2024 at 3:05 AM Paul Menzel <pmenzel@xxxxxxxxxxxxx> wrote:
> 
> > diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
> > index 0ec5f01551f9..9b4ab201fd9a 100644
> > --- a/drivers/net/ethernet/broadcom/tg3.c
> > +++ b/drivers/net/ethernet/broadcom/tg3.c
> > @@ -233,6 +233,10 @@ static int tg3_debug = -1; /* -1 == use TG3_DEF_MSG_ENABLE as value */
> >  module_param(tg3_debug, int, 0);
> >  MODULE_PARM_DESC(tg3_debug, "Tigon3 bitmapped debugging message enable value");
> >
> > +static int short_preamble = 0;
> > +module_param(short_preamble, int, 0);
> > +MODULE_PARM_DESC(short_preamble, "Enable short preamble.");
> > +
> 
> Module parameters are generally not accepted.  If this is something
> other devices can potentially use, it's better to use a more common
> interface.

+1

Most systems supporting suppressed preamble do this using the DT
property 'suppress-preamble'. See:

Documentation/devicetree/bindings/net/mdio.yaml

You could add an ACPI parameter for x86. You could also consider
implementing clock-frequency if the MDIO bus master and all the
devices on the bus support faster than 2.5MHz.

	Andrew