[PATCH v3 mvebu + mvebu/dt64 3/6] firmware: turris-mox-rwtm: fail probing when firmware does not support hwrng

[Andrew Lunn]

On Thu, May 06, 2021 at 11:07:59AM +0200, Pali Rohár wrote:
> When Marvell's rWTM firmware, which does not support the GET_RANDOM
> command, is used, kernel prints an error message
>   hwrng: no data available
> every 10 seconds.
> 
> Fail probing of this driver if the rWTM firmware does not support the
> GET_RANDOM command.
> 
> This makes it possible to put this driver's compatible into generic
> armada-37xx device tree, to be available for other Armada 3720 devices
> besides Turris MOX. If they use the rWTM firmware from CZ.NIC, they will
> have HWRNG available, and if not, the driver won't be complaining.

We start getting into questions of if this is relevant for stable.
Running Turris MOX with plain Marvell rWTM will spam the log. So i
would say it is a fix, for that situation.

However, i would drop the second part of the description. Making the
Turris MOX firmware work on none Turris MOX hardware is a new feature,
and so not applicable to stable.

    Andrew