Re: [PATCH] mdio-bitbang: add support for lowlevel mdio read/write

[Michael Grzeschik <mgr@pengutronix.de>]

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Hi Andrew,

I want to refresh this thread.

On Wed, Jan 29, 2020 at 10:48:05PM +0100, Michael Grzeschik wrote:
>On Wed, Jan 29, 2020 at 04:53:46PM +0100, Andrew Lunn wrote:
>> On Wed, Jan 29, 2020 at 04:42:01PM +0100, Michael Grzeschik wrote:
>> > Hi Andrew!
>> >
>> > I tested your patch. But it works only partially. For the case that
>> > the upper driver is directly communicating in SMI mode with the phy,
>> > this works fine. But the regular MDIO connection does not work anymore
>> > afterwards.
>> >
>> > The normals MDIO communication still needs to work, as mdio-gpio is
>> > calling of_mdiobus_register that on the other end calls get_phy_device
>> > and tries to communicate via regular MDIO to the device.
>>
>> Do you mean you have a mix of devices on the bus, some standards
>> comformant, and others using this hacked up SMI0 mode?
>
>Actually it is the same device used in both modes. The SMI0
>mode is used by the switch driver to address the extended switch
>functions. But on the same bus we have the fec connected to
>the cpu bound fixed-phy (microchip,ks8863) via MDIO.
>
>> You need to specify per device if SMI0 should be used?
>
>Yes, we have to use the same bus fot both modes SMI0 and MDIO.

In fact I for now used the cpu bound port with phy-handle to the fec.
This way it still used mdio for the initial probe.

But it should also work to use fixed-phy for it don't run into mdio
communication on the same bus. This way your patch should work.

In case you did not think of anything else, I will send the series
including your patch after I tested it with master.

Regards,
Michael

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