On 1/24/19 10:19 PM, Carlo Caione wrote:
On 24/01/2019 20:12, Vladimir Oltean wrote:
I still think I haven't successfully made my point. If "mdio read 3.1" is a C45-only thing, "mdio read 1" is a C22-only thing, then why do you need a new command "mdio rmmd 3.1" to do C45 emulation over C22? Is there any overlap I'm missing that mandates a new syntax to differentiate? Can the command not simply see whether the PHY is C22, and if it is and the MMD address is non-zero, just emulate it via 0xd and 0xe writes?
Ok, I got your point now. I didn't give much thought on this TBH, good question.
Do we currently have a way in U-Boot to differentiate between C22 and C45 PHYs? The generic_10g PHY should be C45 but is that the only one currently supported?
-- Carlo Caione
I can't completely answer that, TBH I don't even know who is supposed to make that distinction. For Freescale parts that is a call for the MDIO bus driver to make, for good or bad (see drivers/net/fm/memac_phy.c where dev_addr is compared to MDIO_DEVAD_NONE). And in your patch, phy_write_mmd is only a wrapper over bus->write in the end, with some more logic to handle C22 indirection. So my question of unifying "mdio rmmd" with "mdio read" translates into: Does it make sense to also handle the check with MDIO_DEVAD_NONE in phy_write_mmd, instead of jumping straight ahead to perform indirection? The goal would then be to just call phy_write_mmd from cmd/mdio.c regardless of the target PHY's clause. -Vladimir