On 2021/3/19 11:54, Viresh Kumar wrote:> On 18-03-21, 15:52, Arnd Bergmann wrote:
>> Allowing multiple virtio-i2c controllers in one system, and multiple
i2c
>> devices attached to each controller is clearly something that has to
work.
> Good.
>
>> I don't actually see a limitation though. Viresh, what is the
problem
>> you see for having multiple controllers?
> I thought this would be a problem in that case as we are using the global
> virtio_adapter here.
>
> + vi->adap = &virtio_adapter;
> + i2c_set_adapdata(vi->adap, vi);
>
> Multiple calls to probe() will end up updating the same pointer inside
adap.
>
> + vi->adap->dev.parent = &vdev->dev;
>
> Same here, overwrite.
>
> + /* Setup ACPI node for controlled devices which will be probed
through ACPI */
> + ACPI_COMPANION_SET(&vi->adap->dev, ACPI_COMPANION(pdev));
> + vi->adap->timeout = HZ / 10;
>
> These may be fine, but still not ideal I believe.
>
> + ret = i2c_add_adapter(vi->adap);
> i
> This should be a problem as well, we must be adding this to some sort of
list,
> doing some RPM stuff, etc ?
>
> Jie, the solution is to allocate memory for adap at runtime in probe and
remove
> the virtio_adapter structure completely.
If you want to support that. Then I think we don't need to change the
following at all.
> +??? .algo = &virtio_algorithm,
> +
> +??????? return ret;
> +
> +??? vi->adap = virtio_adapter;
This is strange, why are you allocating memory for adapter twice ?
Once for virtio_adapter and once for vi->adap ? Either fill the fields
directly for v->adap here and remove virtio_adapter or make vi->adap a
pointer.