Re: [PATCH] IIO: hid-sensor-prox: add missing scale attribute

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

On Mon, 2023-10-16 at 08:44 +0100, Jonathan Cameron wrote:
> On Sun, 15 Oct 2023 12:04:48 +0100
> Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > On Sat, 14 Oct 2023 19:56:26 -0700
> > srinivas pandruvada <srinivas.pandruvada@linux.intel.com> wrote:
> > 
> > > On Sat, 2023-10-14 at 17:52 +0100, Jonathan Cameron wrote:  
> > > 
> > 

[...]

> > Phillipp, if a backport makes sense you can request that after this
> > goes upstream.
> Whilst typing up a pull request I saw this again and thought a bit
> more on it.
> 
> This fix is probably wrong approach.  Proximity sensors are often
> scale free
> because they depend on reflectance off something or a capacitance
> changing etc
> so we don't know the scaling.  So the right response then is not to
> return a scale
> value of 1.0 but to not provide the attribute at all.  Is that
> something that
> could be easily done here?

I think so. But hope that iio-sensor-proxy can handle absence of scale
attribute.

git diff drivers/iio/light/hid-sensor-prox.c
diff --git a/drivers/iio/light/hid-sensor-prox.c
b/drivers/iio/light/hid-sensor-prox.c
index a47591e1bad9..e4b81fa948f5 100644
--- a/drivers/iio/light/hid-sensor-prox.c
+++ b/drivers/iio/light/hid-sensor-prox.c
@@ -36,7 +36,6 @@ static const struct iio_chan_spec prox_channels[] = {
                .type = IIO_PROXIMITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
-               BIT(IIO_CHAN_INFO_SCALE) |
                BIT(IIO_CHAN_INFO_SAMP_FREQ) |
                BIT(IIO_CHAN_INFO_HYSTERESIS),
                .scan_index = CHANNEL_SCAN_INDEX_PRESENCE,

Thanks,
Srinivas

> 
> For now I'm dropping the patch. Sorry I wasn't paying enough
> attention to notice
> this was a proximity sensor.
> 
> Jonathan
> 
> > 
> > Thanks,
> > 
> > Jonathan
> > 
> > > > 
> > > > Phillipp - this sounds like a fix to me.  Fixes tag?
> > > > 
> > > > Thanks,
> > > > 
> > > > Jonathan    
> > >   
> > 
>