On 20.09.2021 19:57, Rafał Miłecki wrote:

On 20.09.2021 18:11, Florian Fainelli wrote:

quoted

I believe this leaks np and the use case is not exactly clear to me
here. AFAICT the Northstar SoCs have two MDIO controllers: one for
internal PHYs and one for external PHYs which how you would attach a
switch to the chip (in chipcommonA). Is 53573 somewhat different here?
What is the MDIO bus driver that is being used?

of_get_child_by_name() doesn't seem to increase refcount or anything and
I think it's how most drivers handle it. I don't think it should leak.

BCM53573 is a built with some older blocks. Please check:

4ebd50472899 ("ARM: BCM53573: Initial support for Broadcom BCM53573 SoCs")
     BCM53573 series is a new family with embedded wireless. By marketing
     people it's sometimes called Northstar but it uses different CPU and has
     different architecture so we need a new symbol for it.
     Fortunately it shares some peripherals with other iProc based SoCs so we
     will be able to reuse some drivers/bindings.

e90d2d51c412 ("ARM: BCM5301X: Add basic dts for BCM53573 based Tenda AC9")
     BCM53573 seems to be low priced alternative for Northstar chipsts. It
     uses single core Cortex-A7 and doesn't have SDU or local (TWD) timer. It
     was also stripped out of independent SPI controller and 2 GMACs.

Northstar uses SRAB which is some memory based (0x18007000) access to
switch register space.
BCM53573 uses different blocks & mappings and it doesn't include SRAB at
0x18007000. Accessing switch registers is handled over MDIO.

Florian: did my explanations help reviewing this patch? Would you ack it
now?