Re: [PATCH net v3] net: phy: fix phy_ethtool_set_eee() incorrectly enabling LPI

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Thu, Nov 28, 2024 at 09:44:37AM +0100, Paolo Abeni wrote:
> Hi,
> 
> On 11/23/24 15:50, Russell King (Oracle) wrote:
> > When phy_ethtool_set_eee_noneg() detects a change in the LPI
> > parameters, it attempts to update phylib state and trigger the link
> > to cycle so the MAC sees the updated parameters.
> > 
> > However, in doing so, it sets phydev->enable_tx_lpi depending on
> > whether the EEE configuration allows the MAC to generate LPI without
> > taking into account the result of negotiation.
> > 
> > This can be demonstrated with a 1000base-T FD interface by:
> > 
> >  # ethtool --set-eee eno0 advertise 8   # cause EEE to be not negotiated
> >  # ethtool --set-eee eno0 tx-lpi off
> >  # ethtool --set-eee eno0 tx-lpi on
> > 
> > This results in being true, despite EEE not having been negotiated and:
> >  # ethtool --show-eee eno0
> > 	EEE status: enabled - inactive
> > 	Tx LPI: 250 (us)
> > 	Supported EEE link modes:  100baseT/Full
> > 	                           1000baseT/Full
> > 	Advertised EEE link modes:  100baseT/Full
> > 	                                         1000baseT/Full
> > 
> > Fix this by keeping track of whether EEE was negotiated via a new
> > eee_active member in struct phy_device, and include this state in
> > the decision whether phydev->enable_tx_lpi should be set.
> > 
> > Fixes: 3e43b903da04 ("net: phy: Immediately call adjust_link if only tx_lpi_enabled changes")
> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> 
> This patch did not apply net cleanly to net tree when it was submitted,
> due to its dependency. As a result it did not went through the CI tests.
> Currently there is little material there phy specific - mostly builds
> with different Kconfigs - but with time we hope to increase H/W coverage.
> 
> AFAICS this patch has no kconfig implication, so my local build should
> be a safe-enough test, but please wait for the pre-reqs being merged for
> future submissions.

I guess there's no way to tell the CI tests that another patch is
required? It would be useful if something like a message-id could
indicate to the CI tests that the patch in that message-id is
required.

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