Re: [PATCH v1] driver core: Fix device link device name collision

[Michael Walle]

Am 2021-01-07 10:00, schrieb Greg Kroah-Hartman:
> On Wed, Jan 06, 2021 at 03:26:41PM -0800, Saravana Kannan wrote:
> > The device link device's name was of the form:
> > <supplier-dev-name>--<consumer-dev-name>
> >
> > This can cause name collision as reported here [1] as device names are
> > not globally unique. Since device names have to be unique within the
> > bus/class, add the bus/class name as a prefix to the device names used 
> > to
> > construct the device link device name.
> >
> > So the devuce link device's name will be of the form:
> > <supplier-bus-name>:<supplier-dev-name>--<consumer-bus-name><consumer-dev-name>
>
> Minor nit, you forgot a ':' in the consumer side of the link here.  The
> code is correct.
>
> > [1] - 
> > https://lore.kernel.org/lkml/20201229033440.32142-1-michael@xxxxxxxx/
> > Reported-by: Michael Walle <michael@xxxxxxxx>
> > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
> > ---
> >
> > Michael,
> >
> > Can you please test this? This should fix your issue.
> >
> > Having said that, do you have some local DT changes when you are 
> > testing
> > this? Because it's not obvious from the DT in upstream what dependency
> > is even being derived from the firmware. I don't see any dependency in
> > upstream DT files between mdio_bus/0000:00:00.1 and
> > pci0000:00/0000:00:00.1
>
> That looks really odd, why is the mdio bus using the same names as the
> pci bus?

Logically the MDIO bus belongs to the ENETC, although its actually an 
own
PCI device [1]. What do you think its name should be?

> But anyway, your dev_bus_name() change here looks good, I'll take that
> as a separate patch no matter what happens here :)

I'm just testing this patch, looks like it doesn't fix it for now. But
anyways. Shouldn't there be a Fixes tag for this patch? I.e. 5.11 is
broken right now.

[1] 
https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/freescale/enetc/enetc_pf.c#L748

-michael