Re: [PATCH v2 1/2] misc: Add Nitro Secure Module driver

[Arnd Bergmann]

On Fri, Sep 29, 2023, at 21:26, Alexander Graf wrote:
> On 29.09.23 19:28, Arnd Bergmann wrote:
>> On Fri, Sep 29, 2023, at 09:33, Alexander Graf wrote:

>>
>>> +int nsm_register_hwrng(struct nsm_hwrng *_nsm_hwrng)
>>> +{
>>> +     if (nsm_hwrng)
>>> +             return -EEXIST;
>>> +
>>> +     nsm_hwrng = _nsm_hwrng;
>>> +     if (nsm_vdev)
>>> +             nsm_hwrng->probe(nsm_vdev);
>>> +
>>> +     return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(nsm_register_hwrng);
>> This should get easier of you reverse the dependency between
>> the two drivers and just call into the nsm_hwrng_probe()
>> function from the main driver's probe.
>
>
> I don't understand what you mean by reversing the dependency. Nsm_rng is 
> a downstream of Nsm, because Nsm is the virtio device that owns the channel.

To clarify: I don't really consider Nsm_rng as a downstream driver,
since the main driver does not have a bus model or device detection
below it that would allow probing any function specific drivers.

I would remove the dynamic registration entirely and just merge both
parts into a single file that happens to expose an rng interface.

     Arnd