Re: [PATCH AUTOSEL 6.18-6.1] net: phy: sfp: probe for RollBall I2C-to-MDIO bridge in mdio-i2c

[Petr Wozniak]

Please drop this one from AUTOSEL.

8fe125892f40 was reverted upstream on 2026-06-29 in b521003c27eb
("Revert "net: phy: sfp: probe for RollBall I2C-to-MDIO bridge in
mdio-i2c""), so it is no longer in mainline.

The probe it added runs in SFP_S_INIT, before genuine RollBall modules
have finished initialising their bridge, so the bridge does not answer
CMD_READ/CMD_DONE within the 200 ms window. mdio_protocol is then set
to MDIO_I2C_NONE and PHY detection is skipped for modules that worked
before the commit. Maxime Chevallier and Aleksander Bajkowski both
confirmed that on hardware.

The timing is per-module rather than per-PHY: the FLYPRO
SFP-10GT-CS-30M they tested carries the same AQR113C as a module here
that answers within 200 ms, but needs seconds to load its PHY firmware
from SPI. A fixed probe window cannot cover both, which is why the
commit was reverted rather than adjusted. A proper fix needs per-module
init timing, and per SFF-8472 the host must wait at least 300 ms after
insertion in any case.

Backporting this to stable would reintroduce that regression on
hardware that works there today.

Thanks,
Petr