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

[Paul Menzel]

[Cc: +SONiC Linux kernel maintainers, cf patch submission [1]]

Dear Michael,


Thank you for the quick reply.

Am 02.08.24 um 21:51 schrieb Michael Chan:
> On Fri, Aug 2, 2024 at 3:05 AM Paul Menzel 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.

I saw the patch in the SONiC repository and took a shot at upstreaming 
it. `tg.h` defines the macro:

    #define  MAC_MI_MODE_SHORT_PREAMBLE  0x00000002

Any idea how this should be used? Can it be enabled unconditionally? I 
do not even have the datasheet.


Kind regards,

Paul


[1]: 
https://lore.kernel.org/netdev/20240802100448.10745-1-pmenzel@xxxxxxxxxxxxx/