Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device

Sakari Ailus
2020-12-01T06:47:08Z

Hi Dan,

On Mon, Nov 30, 2020 at 11:06:03PM +0000, Dan Scally wrote:
> Hi Sakari
>
> On 30/11/2020 20:52, Sakari Ailus wrote:
> >> +static const struct acpi_device_id int3472_device_id[] = {
> >> + { "INT3472", 0 },
> > The INT3472 _HID is really allocated for the tps68470 PMIC chip. It may not
> > be used by other drivers; people will want to build kernels where both of
> > these ACPI table layouts are functional.
> >
> > Instead, I propose, that you add this as an option to the tps68470 driver
> > that figures out whether the ACPI device for the tps68470 device actually
> > describes something else, in a similar fashion you do with the cio2-bridge
> > driver. I think it may need a separate Kconfig option albeit this and
> > cio2-bridge cannot be used separately.
>
> It actually occurs to me that that may not work (I know I called that
> out as an option we considered, but that was a while ago actually). The
> reason I wasn't worried about the existing tps68470 driver binding to
> these devices is that it's an i2c driver, and these dummy devices don't
> have an I2cSerialBusV2, so no I2C device is created by them the kernel.
>
>
> Won't that mean the tps68470 driver won't ever be probed for these devices?

Oops. I missed this indeed was not an I²C driver. So please ignore the
comment.

So I guess this wouldn't be an actual problem. I'd still like to test this
on a system with tps68470, as the rest of the set.

--
Kind regards,

Sakari Ailus