Re: [PATCH v10] i2c: virtio: add a virtio i2c frontend driver

Arnd Bergmann
2021-06-30T08:32:18Z

On Wed, Jun 30, 2021 at 10:09 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Wed, Jun 30, 2021 at 09:55:49AM +0200, Arnd Bergmann wrote:
> > On Wed, Jun 30, 2021 at 9:51 AM Jie Deng <jie.deng@intel.com> wrote:
>
> ...
>
> > On a related note, we are apparently still missing the bit in the virtio bus
> > layer that fills in the dev->of_node pointer of the virtio device. Without
> > this, it is not actually possible to automatically probe i2c devices connected
> > to a virtio-i2c bus. The same problem came up again with the virtio-gpio
> > driver that suffers from the same issue.
>
> Don't we need to take care about fwnode handle as well?

I'm fairly sure this gets set up automatically on DT based systems, based
on the dev->of_node of the virtio device, with no changes to the i2c
core core.

If you want to automatically probe i2c devices on a virtio-i2c controller
with ACPI, I have no idea if that would require changes to both
i2c-core-acpi.c as well as the virtio core, or just one of them.
So far, my assumption was that this would not be needed with ACPI.

Arnd