Comment about unstable DSA devicetree binding in marvell.txt

Comment about unstable DSA devicetree binding in marvell.txt

[Andreas Svensson]

Hi,

I'm looking at using mv88e6xxx-mdio-external for the external MDIO
bus to communicate with a PHY.

I couldn't help but notice the comment about the devicetree binding
being unstable in Documentation/devicetree/bindings/net/dsa/marvell.txt:

"WARNING: This binding is currently unstable. Do not program it into a
FLASH never to be changed again. Once this binding is stable, this
warning will be removed."

Any update on this, is marvell.txt still considered unstable?

Best Regards,
Andreas Svensson

Re: Comment about unstable DSA devicetree binding in marvell.txt

[Andrew Lunn]

On Mon, Mar 21, 2022 at 06:03:59PM +0100, Andreas Svensson wrote:
> Hi,
> 
> I'm looking at using mv88e6xxx-mdio-external for the external MDIO
> bus to communicate with a PHY.
> 
> I couldn't help but notice the comment about the devicetree binding
> being unstable in Documentation/devicetree/bindings/net/dsa/marvell.txt:
> 
> "WARNING: This binding is currently unstable. Do not program it into a
> FLASH never to be changed again. Once this binding is stable, this
> warning will be removed."
> 
> Any update on this, is marvell.txt still considered unstable?

I personally would never write it to FLASH never to be changed
again. I would always load the DT blob from disk, a version which
matches the kernel. DT blobs do contain bugs and they need to be
fixed.

The marvell binding has not changed for a long time, so in practice
you can consider it stable. But just because it is stable does not
mean DT blobs are bug free.

     Andrew

Re: Comment about unstable DSA devicetree binding in marvell.txt

[Andreas Svensson]

On Mon, Mar 21, 2022 at 6:17 PM Andrew Lunn <andrew@lunn.ch> wrote:
>
> On Mon, Mar 21, 2022 at 06:03:59PM +0100, Andreas Svensson wrote:
> > Hi,
> >
> > I'm looking at using mv88e6xxx-mdio-external for the external MDIO
> > bus to communicate with a PHY.
> >
> > I couldn't help but notice the comment about the devicetree binding
> > being unstable in Documentation/devicetree/bindings/net/dsa/marvell.txt:
> >
> > "WARNING: This binding is currently unstable. Do not program it into a
> > FLASH never to be changed again. Once this binding is stable, this
> > warning will be removed."
> >
> > Any update on this, is marvell.txt still considered unstable?

Thanks for the fast reply Andrew.

> I personally would never write it to FLASH never to be changed
> again. I would always load the DT blob from disk, a version which
> matches the kernel. DT blobs do contain bugs and they need to be
> fixed.

Totally agree.

> The marvell binding has not changed for a long time, so in practice
> you can consider it stable. But just because it is stable does not
> mean DT blobs are bug free.

This is my understanding as well. I have not found any issues so far
using mv88e6xxx-mdio-external which is marvell binding specific.

Thanks for the clarification about the comment!

Best Regards,
Andreas