Re: [PATCH 1/1] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

On Sun, Jan 29, 2023 at 8:52 AM Andrew Lunn [off-list ref] wrote:

On Sat, Jan 28, 2023 at 06:26:15PM -0800, Chris Healy wrote:

quoted

From: Chris Healy <redacted>

The Meson G12A Internal PHY does not support standard IEEE MMD extended
register access, therefore add generic dummy stubs to fail the read and
write MMD calls. This is necessary to prevent the core PHY code from
erroneously believing that EEE is supported by this PHY even though this
PHY does not support EEE, as MMD register access returns all FFFFs.

Hi Chris

This change in itself makes sense. But i wounder if we should also
change phy_init_eee(). It reads the EEE Ability register. The 2018
version of the standard indicates the top two bits are reserved and
should be zero. We also don't have any PHY which supports 100GBase-R
through to 100Base-TX. So a read of 0xffff suggests the PHY does not
support EEE and returning -EPROTONOSUPPORT would be good.

This seems like a good change to make in phy_init_eee().  I should be
able to do this.  Can this be done in a subsequent patch or does this
need to be present to land this meson specific PHY patch?

        Andrew