Re: [PATCH net-next] net: dsa: mt7530: fix support for MT7531BE

From: Arınç ÜNAL
Date: Tue Apr 11 2023 - 15:31:02 EST


On 11.04.2023 03:11, Daniel Golle wrote:
There are two variants of the MT7531 switch IC which got different
features (and pins) regarding port 5:
* MT7531AE: SGMII/1000Base-X/2500Base-X SerDes
* MT7531BE: RGMII

Moving the creation of the SerDes PCS from mt753x_setup to mt7530_probe
with commit 6de285229773 ("net: dsa: mt7530: move SGMII PCS creation to
mt7530_probe function") works fine for MT7531AE which got two instances
of mtk-pcs-lynxi, however, MT7531BE requires mt7531_pll_setup to setup
clocks before the single PCS on port 6 (usually used as CPU port)
starts to work and hence the PCS creation failed on MT7531BE.

Fix this by introducing a pointer to mt7531_create_sgmii function in
struct mt7530_priv and call it again at the end of mt753x_setup like it
was before commit 6de285229773 ("net: dsa: mt7530: move SGMII PCS
creation to mt7530_probe function").

If I understand correctly, this patch does two things.

Run mt7531_create_sgmii() from mt753x_setup(), after mt7531_setup() and mt7531_setup_common() is run so that PCS on MT7531BE works.

Run the PCS creation code inside the loop only once if mt7531_dual_sgmii_supported() is false so it doesn't set the nonexistent port 5 SGMII on MT7531BE.

Regarding the first part:
I was actually in the middle of moving the code until after mt7530_pll_setup() and mt7531_pll_setup() on mt7530_setup() and mt7531_setup() to mt7530_probe(). To me it makes more sense to run them on mt7530_probe() as there's a good amount of duplicate code on mt7530_setup() and mt7531_setup().

This will resolve the problem here, and make my future work regarding the PHY muxing feature on the MT7530 switch possible to do.

Regarding the second part:
I'll take your changes to my current RFC patch series while addressing Jesse's suggestion if this is fine by you.

Arınç