net: phy: qca83xx: read resolved QCA8337 link status

After a QCA8337 SmartSpeed downshift, genphy_read_status() can report
1000 Mbit/s from the advertised modes when the PHY is running at
100 Mbit/s. On a Redmi AX5400 running downstream OpenWrt Linux 6.18.52,
this caused qca8k to program the user-port MAC for 1000 Mbit/s and
traffic failed. An earlier prototype that read the resolved speed
from the PHY restored traffic.

Wrap genphy_read_status() and use at803x_read_specific_status() to
replace its speed and duplex result when an autonegotiated link comes
up. Resolve pause for the resulting duplex. Until the PHY reports a
resolved speed and duplex, report the link as down so that the next
poll reads them again, as marvell_read_status_page_an() does. In that
case also clear the duplex, master/slave state and link partner modes
that genphy_read_status() read for an up link. QCA8337's register
layout matches the helper (data sheet 80-Y0619-3 Rev. D, pages
327-328).

Keep the generic master/slave read order and the early return for a
steady autonegotiated link. This avoids additional reads of the
clear-on-read idle error count in MII_STAT1000. Forced mode continues
to use BMCR. Report the MDI-X state read at link-up and invalidate it
when the link goes down or autonegotiation is disabled. Clear
mdix_ctrl because this driver does not implement MDI-X configuration.

The QCA8327 entries keep genphy_read_status(). The AR8327 data sheet
(MKG-15791 Rev. 1.0) lists the QCA8327-A PHY ID and documents the same
PHY-specific status layout, with SmartSpeed enabled after a hardware
reset, so those PHYs may have the same problem. That is untested on
QCA8327 hardware, so limit this change to QCA8337.

Fixes: b3591c2a3661 ("net: dsa: qca8k: Switch to PHYLINK instead of PHYLIB")
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Yongzhao Chen <yongzhao.derek@gmail.com>
Assisted-by: LLM
Link: https://patch.msgid.link/20261013190339.51909-1-yongzhao.derek@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

0 files changed, 0 insertions, 0 deletions