Re: [PATCH net-next] net: stmmac: Fix the case when PHY handle is not present

[Katsuhiro Suzuki]

Hello Andrew,

On 2019/06/25 23:51, Andrew Lunn wrote:
> On Tue, Jun 25, 2019 at 11:40:00PM +0900, Katsuhiro Suzuki wrote:
> > Hello Jose,
> >
> > This patch works fine with my Tinker Board. Thanks a lot!
> >
> > Tested-by: Katsuhiro Suzuki <katsuhiro@xxxxxxxxxxxxx>
> >
> >
> > BTW, from network guys point of view, is it better to add a phy node
> > into device trees that have no phy node such as the Tinker Board?
>
> Hi Katsuhiro
>
> It makes it less ambiguous if there is a phy-handle. It is then very
> clear which PHY should be used. For a development board, which people
> can be tinkering around with, there is a chance they add a second PHY
> to the MDIO bus, or an Ethernet switch, etc. Without explicitly
> listing the PHY, it might get the wrong one. However this is generally
> a problem if phy_find_first() is used. I think in this case, something
> is setting priv->plat->phy_addr, so it is also clearly defined which
> PHY to use.
>
> 	  Andrew

Hmm, I see. This stmmac driver can choose PHY by the kernel module
parameter 'phyaddr' (if no one set this parameter, priv->plat->phy_addr
goes to 0). So there is no ambiguous in this case and need no changes
for device tree.

Thank you for your comment.

Best Regards,
Katsuhiro Suzuki