[SOLVED] LXT973 support (dual PHY with single MDIO)

[Andy Fleming]

On May 30, 2006, at 09:22, Vitaly Bordug wrote:

> On Tue, 30 May 2006 11:28:48 +0200
> Laurent Pinchart <laurent.pinchart at tbox.biz> wrote:
>
>> Hi,
>>
>> once again, posting to a mailing list helped me solving my  
>> problem. It should
>> have been obvious that the MDIO bus is really a bus, and can as  
>> such support
>> several devices. The issue was that the drivers/net/fs_enet driver  
>> set
>> bus->phy_mask to ~0x9, and the LXT973 uses addresses 0 and 1.  
>> Address 1 thus
>> never got probed. What's the reason for probing addresses 0 and 3  
>> only ?
>
> The reason is obvious: bitbang read of PHY id with not-existent  
> PHY, does not return expected (0, iirc), that confuse mdio bus  
> device-driver bound (it assumes error and returns -1), and prevents  
> from probing other phys. So, as that seems to be a "feature" on  
> CPM2 only, we are working that around specifying phy_mask to  
> prevent probing inexistent phys w/over bitbang thing.


Hopefully, this isn't being set in the driver, but is set in the  
board code, instead.  This is a board-specific setting.

Andy