Re: [PATCH RFC net-next 0/4] net: pse-pd: decouple controller lookup from MDIO probe

[Carlo Szelinsky <github@szelinsky.de>]

Hi,

I tested the series on a Hasivo S1100WP-8GT-SE with hs104 PSE
chips. Boot is clean, no more probe loop. ethtool --set-pse on/off
works, and a PD plugged into a port gets power. So the fix works
for me.

One thing I noticed: rmmod alone does not work while ports are
attached. Each PHY that holds a psec keeps a ref on the PSE
driver, so the module count stays above 0 and rmmod fails.

Unbinding the i2c devices first works:
  echo 0-000d > /sys/bus/i2c/drivers/hasivo-hs104/unbind
  echo 0-0015 > /sys/bus/i2c/drivers/hasivo-hs104/unbind
  rmmod hasivo-hs104

After unbind your PSE_UNREGISTERED notifier fires, the PHYs drop
the psec, and the module count goes to 0. Then rmmod works.

Not a big deal, but maybe worth a short note in the cover letter
so people know they need to unbind first. Or if there is a clean
way to skip the per-consumer module_get and just rely on the
unbind path, that would be nice too. What do other folks think?

One thing my test does not cover yet is the SFP path change in
sfp.c, since the S1100WP-8GT-SE is copper only. I do have an
S600WP-5GT-2SX-SE that uses the same hs104 chips plus SFP+ cages,
but it is not on my desk right now. I can run that part on it
later.

Anyway, thanks for the work on this. Happy to test a v2.

Carlo

Tested-by: Carlo Szelinsky <github@szelinsky.de>