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

From: Katsuhiro Suzuki
Date: Tue Jun 25 2019 - 11:27:23 EST

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.


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