Re: [PATCH v2] iio: bme680_i2c: Remove ACPI support

[Andy Shevchenko]

On Thu, May 6, 2021 at 4:37 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> On Thu, May 06, 2021 at 12:28:40PM +0300, Andy Shevchenko wrote:
> > On Thu, May 6, 2021 at 6:43 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > >
> > > With CONFIG_ACPI=n and -Werror, 0-day reports:
> > >
> > > drivers/iio/chemical/bme680_i2c.c:46:36: error:
> > >         'bme680_acpi_match' defined but not used
> > >
> > > Apparently BME0680 is not a valid ACPI ID. Remove it and with it
> > > ACPI support from the bme680_i2c driver.
> >
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> >
> > with the SPI part amended in the same way.
> >
> Right. I just sent a patch doing that. Oddly enough 0-day didn't complain
> about that one to me, nor about many other drivers with the same problem.
> No idea how it decides if and when to make noise.

randconfig I believe.

> Is there a way to determine invalid ACPI IDs ? I could write a coccinelle
> script to remove the code automatically.

As Hans said...

My understanding that most of the fake IDs come into life due to:
 - people apply similar rules to them as they knew about OF case (and
certain maintainers blindly allowed that)
 - people in big companies need to quickly prototype something without
giving a crap about ACPI specification and / or process

The last part (I believe the smallest one) is vendors who heard about
ACPI, but haven't enough knowledge about the process.

-- 
With Best Regards,
Andy Shevchenko