Re: [PATCH net v3 1/2] net: dsa: mt7530: populate lpi_interfaces to fix EEE support

[Paolo Abeni <pabeni@redhat.com>]

On 8/27/26 11:16 PM, Aleksei Sviridkin wrote:
> phylink_create() decides once and for all that a MAC supports managed
> EEE, and it requires the tx_lpi ops plus non-empty lpi_capabilities and
> lpi_interfaces. mt753x_phylink_get_caps() leaves lpi_interfaces empty.
> 
> So ever since the conversion to phylink managed EEE, ethtool has
> answered "Not supported" on every mt753x port, and phy_disable_eee()
> has locked userspace out of turning EEE on. That undoes what
> commit 06dfcd4098cf ("net: dsa: mt7530: fix enabling EEE on MT7531
> switch on all boards") arranged: EEE off by default, but reachable
> with ethtool.
> 
> Leave the speeds above 1 Gbps out of both bitmaps. PMCR folds
> SPEED_2500 and SPEED_10000 onto PMCR_FORCE_SPEED_1000, so
> PMCR_FORCE_EEE1G would govern LPI on such a link, and that is
> unvalidated rather than known unsupported: MediaTek's SDK driver sets
> the EEE force bits for 100 Mbps and 1 Gbps only, and the unit of the
> wakeup timers is undocumented with the port clock at 2.5 times the
> rate.
> 
> LPI stays off until userspace enables it, but the EEE advertisement of
> a PHY that advertises it out of reset comes back, since phylink stops
> force-clearing it.
> 
> Fixes: 9cf21773f535 ("net: dsa: mt7530: convert to phylink managed EEE")
> Signed-off-by: Aleksei Sviridkin <f@lex.la>
> ---
> 
> Ports that support neither 100 Mbps nor 1 Gbps are skipped because on
> MT7988, EN7581 and AN7583 port 6 is 10 Gbps only and shares
> PHY_INTERFACE_MODE_INTERNAL with the user ports, so the interface mask
> alone cannot tell them apart. MT7531's internal PHYs keep the
> advertisement mt7531_setup() zeroed and EN7528 keeps both bitmaps
> empty, so EEE stays fully off there.
> 
> Two pre-existing things this patch makes live, neither addressed here:
> 
> - The unit of LPI_THRESH is still unspecified, as the comment above
>   lpi_timer_default says. ethtool now reports 30 for a switch port
>   against 1000 for the SoC MAC, which is a driver constant already in
>   microseconds, and mtk_eth_soc treats a structurally identical field
>   as milliseconds. Does anyone have the datasheet answer?

Clashiko complains about the above:

https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260827211652.63504-1-f%40lex.la

@Andrew: WDYT?

/P