Revert "net: phy: sfp: probe for RollBall I2C-to-MDIO bridge in mdio-i2c"

This reverts commit 8fe125892f40 ("net: phy: sfp: probe for RollBall
I2C-to-MDIO bridge in mdio-i2c").

That commit added a RollBall bridge probe at MDIO bus creation time, in
i2c_mii_init_rollball(), to avoid a multi-minute PHY probe retry loop on
modules without a bridge (e.g. RTL8261BE). The probe runs in SFP_S_INIT,
before genuine RollBall modules have finished their firmware/bridge
initialization, so the bridge does not yet answer CMD_READ/CMD_DONE. The
probe times out, mdio_protocol is set to MDIO_I2C_NONE, and PHY detection
is then skipped for genuine RollBall modules that worked before the commit.

This was confirmed on hardware by Maxime Chevallier and Aleksander
Bajkowski: their RollBall modules no longer detect a PHY, and work again
on v7.0 (before the bridge probing was introduced). The Sashiko static
review flagged the same path.

Deferring the probe to PHY discovery time does not fix it either: at that
point a slow module may still be initializing, so the probe still returns
-ENODEV. A proper fix needs per-module init timing (a longer module_t_wait
or a per-module quirk, per SFF-8472 the host must also wait at least 300 ms
after insertion), which requires genuine RollBall hardware to develop and
validate. Revert to restore the previous, working behaviour in the meantime.

The RTL8261BE retry-loop latency that the reverted commit addressed is
handled in our downstream tree, so reverting upstream is safe on our side.

Fixes: 8fe125892f40 ("net: phy: sfp: probe for RollBall I2C-to-MDIO bridge in mdio-i2c")
Reported-by: Aleksander Bajkowski <olek2@wp.pl>
Suggested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://lore.kernel.org/netdev/20260624084814.20972-1-petr.wozniak@gmail.com/
Signed-off-by: Petr Wozniak <petr.wozniak@gmail.com>
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/23e3931915c3ed2a14cec95f1490e43d30b225e8.1782581445.git.petr.wozniak@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions