Re: [PATCH net v2 2/2] net: dsa: mt7530: fix disabling EEE on failure on MT7531 and MT7988

From: Paolo Abeni
Date: Tue Mar 26 2024 - 05:04:43 EST


On Thu, 2024-03-21 at 19:29 +0300, Arınç ÜNAL via B4 Relay wrote:
> From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
>
> The MT7531_FORCE_EEE1G and MT7531_FORCE_EEE100 bits let the
> PMCR_FORCE_EEE1G and PMCR_FORCE_EEE100 bits determine the 1G/100 EEE
> abilities of the MAC. If MT7531_FORCE_EEE1G and MT7531_FORCE_EEE100 are
> unset, the abilities are left to be determined by PHY auto polling.
>
> The commit 40b5d2f15c09 ("net: dsa: mt7530: Add support for EEE features")
> made it so that the PMCR_FORCE_EEE1G and PMCR_FORCE_EEE100 bits are set on
> mt753x_phylink_mac_link_up(). But it did not set the MT7531_FORCE_EEE1G and
> MT7531_FORCE_EEE100 bits. Because of this, EEE will be enabled on the
> switch MACs by polling the PHY, regardless of the result of phy_init_eee().
>
> Define these bits and add them to MT7531_FORCE_MODE which is being used by
> the subdriver. With this, EEE will be prevented from being enabled on the
> switch MACs when phy_init_eee() fails.
>
> Fixes: 40b5d2f15c09 ("net: dsa: mt7530: Add support for EEE features")
> Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>

If I read the past discussion correctly, this is a potential issue
found by code inspection and never producing problem in practice, am I
correct?

If so I think it will deserve a 3rd party tested-by tag or similar to
go in.

If nobody could provide such feedback in a little time, I suggest to
drop this patch and apply only 1/2.

Cheers,

Paolo