[PATCH net-next v5 0/5] Support for RollBall 10G copper SFP modules

Marek Behún
2021-01-14T04:44:38Z

Hello,

this is v5 of series adding support for RollBall/Hilink SFP modules.

Checked with:
checkpatch.pl --max-line-length=80

Changes from v4:
- added patch adding SFP_PASSWORD = 0x7b to sfp.h
- patch adding RollBall MDIO I2C protocol support
- removed forgotten comment that was no longer true
- we now try to restore the page if the I2C transfer failed
- unfortunately we cannot simply move the code to do paged I2C
transfers to sfp.c, because sfp.c depends on code inmdio-i2c.c,
and if we added dependency the other way, I don't know what
would happen to module loader (since both SFP and MDIO_I2C can
be compiled as modules).
This can be refactored later, when someone needs paged I2C
accesses in sfp.c
- added Reviewed-by tags

Changes from v3:
- RollBall mdio-i2c driver now sets/restores SFP_PAGE for every MDIO
access.
I first wanted to achieve this operation (setting
SFP_PAGE/doing MDIO/restoring SFP_PAGE) via one call do i2c_transfer,
by constructing msgs array in such a way, but it turned out that this
doesn't work on RollBall SFPs, because changed SFP_PAGE takes into
account only after i2c_transfer ends.
So instead I use i2c_lock_bus/serveral __i2c_transfers/i2c_unlock_bus.
- I have removed the patch which changes MACTYPE in the marvell10g
driver, since Russell has in his net-queue a better solution. I still
think that my patch would have sufficed temporarily (and would not
cause regressions), but nobody wanted to review it. If you think that
I should sent this series again with that patch, please let me know.

Changes from v2:
- added comment into the patch adding support for RollBall I2C MDIO
protocol, saying that we expect the SFP_PAGE not to be changed by
the SFP code, as requested by Russell. If, in the future, SFP code
starts modifying SFP_PAGE, we will have to handle it in mdio-i2c
somehow
- destruction of I2C MDIO bus in patch 3/5 now depends on whether the
MDIO bus is not NULL, instead of whether PHY exists, as suggested by
Russell
- changed waiting time for RollBall module to initialize from 30 seconds
to 25 seconds. Testing shows that it is never longer than 21-22
seconds, so waiting 25 seconds instead of 30 is IMO safe enough
- added Russell's Reviewed-by tags where relevant

Changes from v1:
- wrapped to 80 columns as per Russell's request
- initialization of RollBall MDIO I2C protocol moved from sfp.c to
mdio-i2c.c as per Russell's request
- second patch removes the 802.3z check also from phylink_sfp_config
as suggested by Russell
- creation/destruction of mdiobus for SFP now occurs before probing
for PHY/after releasing PHY (as suggested by Russell)
- the last patch became a little simpler after the above was done

Marek

Marek Behún (5):
net: sfp: add SFP_PASSWORD address
net: phy: mdio-i2c: support I2C MDIO protocol for RollBall SFP modules
net: phylink: allow attaching phy for SFP modules on 802.3z mode
net: sfp: create/destroy I2C mdiobus before PHY probe/after PHY
release
net: sfp: add support for multigig RollBall transceivers

drivers/net/mdio/mdio-i2c.c | 308 +++++++++++++++++++++++++++++++++-
drivers/net/phy/phylink.c | 5 +-
drivers/net/phy/sfp.c | 66 ++++++--
include/linux/mdio/mdio-i2c.h | 8 +-
include/linux/sfp.h | 1 +
5 files changed, 368 insertions(+), 20 deletions(-)

base-commit: 0ae5b43d6dde6003070106e97cd0d41bace2eeb2
--
2.26.2