Re: [Bug 219890] illuminance sensor is jittering between correct value and 0.03lux

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 17 Mar 2025 13:02:24 +0000
bugzilla-daemon@kernel.org wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=219890
> 
> --- Comment #2 from wysiwyg81@rbox.co ---
> Hello, Did you mean in /sys/bus/iio/devices/ instead of 
> /sys/iio/devices/ if so: /sys/bus/iio/devices ❯ ls -lh Permissions Size 
> User Date Modified Name lrwxrwxrwx - root 17 mars 13:43  iio:device0 -> 
> ../../../devices/pci0000:00/0000:00:14.0/usb3/3-8/3-8:1.0/0003:17EF:F006.000E/HID-SENSOR-200041.6.auto/iio:device0 
> lrwxrwxrwx - root 17 mars 13:43  iio:device1 -> 
> ../../../devices/pci0000:00/0000:00:14.0/usb3/3-8/3-8:1.0/0003:17EF:F006.000E/HID-SENSOR-200041.7.auto/iio:device1 
> lrwxrwxrwx - root 17 mars 13:43  trigger0 -> 
> ../../../devices/pci0000:00/0000:00:14.0/usb3/3-8/3-8:1.0/0003:17EF:F006.000E/HID-SENSOR-200041.6.auto/trigger0 
> lrwxrwxrwx - root 17 mars 13:43  trigger1 -> 
> ../../../devices/pci0000:00/0000:00:14.0/usb3/3-8/3-8:1.0/0003:17EF:F006.000E/HID-SENSOR-200041.7.auto/trigger1
> 
> (bugzilla seems down currently, so I try direct email answer, hope it 
> works, I will check once bugzilla is back).
Perfect.  So it is definitely a hid sensor.
Srinivas any idea?
> 
> Best regards,
> 
> On 17/03/2025 13:15, bugzilla-daemon@kernel.org wrote:
> > https://bugzilla.kernel.org/show_bug.cgi?id=219890
> >
> > --- Comment #1 from Jonathan Cameron (jic23@kernel.org) ---
> > On Mon, 17 Mar 2025 09:38:50 +0000
> > bugzilla-daemon@kernel.org wrote:
> >  
> >> https://bugzilla.kernel.org/show_bug.cgi?id=219890
> >>
> >>              Bug ID: 219890
> >>             Summary: illuminance sensor is jittering between correct value
> >>                      and 0.03lux
> >>             Product: Drivers
> >>             Version: 2.5
> >>            Hardware: All
> >>                  OS: Linux
> >>              Status: NEW
> >>            Severity: normal
> >>            Priority: P3
> >>           Component: IIO
> >>            Assignee: drivers_iio@kernel-bugs.kernel.org
> >>            Reporter: wysiwyg81@rbox.co
> >>          Regression: No
> >>
> >> Hello,
> >>
> >> I have a Lenovo thinkbook 13x gen4.
> >> Automatic brightness control is flickering in Gnome, so I checked sensor
> >> with
> >> monitor-sensor command (iio-sensor-proxy).
> >>
> >> it shows following behavior:
> >> monitor-sensor  --light
> >>      Waiting for iio-sensor-proxy to appear
> >> +++ iio-sensor-proxy appeared
> >> === Has ambient light sensor (value: 316,000000, unit: lux)
> >>      Light changed: 299,000000 (lux)
> >>      Light changed: 0,030000 (lux)
> >>      Light changed: 299,000000 (lux)
> >>      Light changed: 0,030000 (lux)
> >>      Light changed: 299,000000 (lux)
> >>      Light changed: 0,030000 (lux)
> >>      Light changed: 305,000000 (lux)
> >>
> >>
> >> the 0.03 is unexpected has it has never been that dark.
> >> it seems it's not a iio-sensor-proxy bug as I can see similar behavior by
> >> checking directly content of here :
> >> /sys/bus/iio/devices/iio:device0/in_illuminance_raw
> >>
> >>
> >> I checked the behavior on windows to make sure it's not an hardware failure
> >> from my sensor.
> >> While I cannot have direct access to raw sensor data on windows, the
> >> automatic
> >> brightness is perfectly smooth: no flickering of any kind.
> >>
> >> I didn't found sensor name:
> >> ❯ cat  /sys/bus/iio/devices/iio:device0/name
> >> als  
> > Two possibles types. It's either a hid sensor or an ACPI class interface
> > with a sensor wrapped up in firmware.
> >
> > My guess is hid-sensor.  Can you do an
> > ls -lh in /sys/iio/devices/
> > so we can see what the parent is.
> > +CC Srinivas based on playing guess the sensor.
> >
> > Jonathan
> >
> >
> >
> >
> >  
> >> But if there is other place I could look, let me know.
> >>  
>