Re: [PATCH net-next 2/3] net: bcmgenet: Pass "main" clock down to the MDIO driver

[Florian Fainelli]

On 2/16/24 14:41, Jacob Keller wrote:
> On 2/16/2024 10:42 AM, Florian Fainelli wrote:
> > GENET has historically had to create a MDIO platform device for its
> > controller and pass some auxiliary data to it, like a MDIO completion
> > callback. Now we also pass the "main" clock to allow for the MDIO bus
> > controller to manage that clock adequately around I/O accesses.
> >
> > Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
> > ---
> >   drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> > index cbbe004621bc..7a21950da77c 100644
> > --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
> > +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> > @@ -476,6 +476,10 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv)
> >   	ppd.wait_func = bcmgenet_mii_wait;
> >   	ppd.wait_func_data = priv;
> >   	ppd.bus_name = "bcmgenet MII bus";
> > +	/* Pass a reference to our "main" clock which is used for MDIO
> > +	 * transfers
> > +	 */
> > +	ppd.clk = priv->clk;
> >   
> >   	/* Unimac MDIO bus controller starts at UniMAC offset + MDIO_CMD
> >   	 * and is 2 * 32-bits word long, 8 bytes total.
>
> Is this missing a modification of the header file to add the clk field
> to struct unimac_mdio_pdata? I don't see that field in the
> include/linux/platform_data/mdio-bcm-unimac.h header currently...
>
> Oh. you included that in the first patch of the series. I see.

I suppose I could have included it in patch #1, and have introduced in 
patch #2 the hunk that dealt with fetching pdata->clk, but since I was 
re-organizing the mdio-bcm-unimac.c driver's probe function, it felt 
more natural to arrange it that way.

> It feels like the series would be more natural of this was 1/3 instead
> of 2/3, since the current 1/3 patch depends on this clk value being set, no?

I sort of debated that with myself, and ended up going with: put the 
plumbing first, wire it later, rather than the opposite. If someone was 
to run a bisection there would not be any difference in behavior until 
patch #2 regardless of their ordering.

> The result of the series makes sense tho:
>
> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>

Thanks Jacob!
--
Florian

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