Re: [PATCH 1/4] dt-bindings: net: dsa: nxp,sja1105: Add reset-gpios property

On 25-09-10, Vladimir Oltean wrote:

On Wed, Sep 10, 2025 at 05:53:59PM +0200, Marco Felsch wrote:

quoted

IMHO silently removing the support will break designs for sure and
should never be done. As said, imagine that the firmware will handle the
supplies and the driver only needs to release the reset. If you silently
remove the support, the device will be kept in reset-state. In field
firmware updates are seldom, so you break your device by updating to a
new kernel.

One could argue that the driver supported it but there was no dt-binding
yet, so it was a hidden/unstable feature but I don't know the policy.

Ok, I didn't think about, or meet, the case where Linux is required by
previous boot stages to deassert the reset. It is the first time you are
explicitly saying this, though.

So we can keep and document the 'reset-gpios' support, but we need to
explicitly point out that if present, it does not supplant the need to
ensure the proper POR sequence as per AH1704.

We could do that but I think that no one should assume that the driver
ensures this due to the missing power-supply and clock support. But this
goes to the DT maintainers. IMHO we shouldn't mention any document
within the binding, maybe within the commit message, since those
documents may get removed.

Regards,
  Marco