Re: Issues with Lenovo Yoga 900 IIO devices (accelerometer, etc.)

[Nish Aravamudan]

On Thu, Dec 17, 2015 at 9:32 AM, Nish Aravamudan
<nish.aravamudan@xxxxxxxxx> wrote:
> On Thu, Dec 17, 2015 at 12:41 AM, Crt Mori <cmo@xxxxxxxxxxx> wrote:
>> On 17 December 2015 at 06:27, Nish Aravamudan <nish.aravamudan@xxxxxxxxx> wrote:
>>> On Wed, Dec 16, 2015 at 3:05 PM, Nish Aravamudan
>>> <nish.aravamudan@xxxxxxxxx> wrote:
>>>> On Wed, Dec 16, 2015 at 2:55 PM, Crt Mori <cmo@xxxxxxxxxxx> wrote:
>>>>>
>>>>> On Dec 16, 2015 11:37 PM, "Nish Aravamudan" <nish.aravamudan@xxxxxxxxx>
>>>>> wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> On Wed, Dec 16, 2015 at 2:22 PM, Crt Mori <cmo@xxxxxxxxxxx> wrote:
>>>>>> > On 16 December 2015 at 22:41, Nish Aravamudan
>>>>>> > <nish.aravamudan@xxxxxxxxx> wrote:
>>>>>> >> Hi Daniel,
>>>>>> >>
>>>>>> >> On Wed, Dec 16, 2015 at 1:43 AM, Daniel Baluta
>>>>>> >> <daniel.baluta@xxxxxxxxx> wrote:
>>>>>> >>> On Tue, Dec 15, 2015 at 9:19 PM, Nish Aravamudan
>>>>>> >>> <nish.aravamudan@xxxxxxxxx> wrote:
>>>>>> >>>> So, I apologize in advance for this relatively vague report, but I'm
>>>>>> >>>> fairly sure
>>>>>> >>>> the Yoga 900 has an accelerometer amongst other sensors (ambient
>>>>>> >>>> light?)
>>>>>> >>>> exported over IIO.
>>>>>> >>>>
>>>>>> >>>> But, these sensors seem to not be updating at all with a 4.4-rc5+
>>>>>> >>>> kernel (a
>>>>>> >>>> set of patches from https://lkml.org/lkml/2015/11/30/441 applied to
>>>>>> >>>> Linus'
>>>>>> >>>> tree).
>>>>>> >>>>
>>>>>> >>>> The odd part is at some point in messing with this, I'm fairly sure
>>>>>> >>>> it did work!
>>>>>> >>>> That is,
>>>>>> >>>>
>>>>>> >>>> `watch -n 0.1 cat '/sys/bus/iio/devices/iio:device'*/*raw*`
>>>>>> >>>
>>>>>> >>> Can you send us a sample of the output? Also, would be
>>>>>> >>> good to identify the exact driver for accel.
>>>>>> >>
>>>>>> >> cat /sys/bus/iio/devices/iio:device*/*raw*
>>>>>> >> 65478
>>>>>> >> 7
>>>>>> >> 1023
>>>>>> >> 0
>>>>>> >> 0
>>>>>> >> 0
>>>>>> >> 100
>>>>>> >> -539062
>>>>>> >> -742187
>>>>>> >> 1292968
>>>>>> >> 1592
>>>>>> >> 64932
>>>>>> >> 2
>>>>>> >> 275
>>>>>> >> 0 0 0 0
>>>>>> >>
>>>>>> >> Now, I should say that I distinctly remember at some point waving my
>>>>>> >> laptop around and seeing these values change ... but now they seem to
>>>>>> >> be "stuck". Maybe it's a hardware issue or something special that
>>>>>> >> WIndows does to leverage the IIO sensors?
>>>>>> >>
>>>>>> >>> Perhaps: cat /sys/bus/iio/devices/iio:device'*/name
>>>>>> >>
>>>>>> >> $ cat /sys/bus/iio/devices/iio:device*/name
>>>>>> >> accel_3d
>>>>>> >
>>>>>> > Can you list the directory of iio:device with this name (it is:
>>>>>> > drivers/iio/accel/hid-sensor-accel-3d.c).
>>>>>> > This is something you will be looking at for accel debugging, but it
>>>>>> > seems more like
>>>>>> > standard
>>>>>>
>>>>>> /sys/bus/iio/devices/iio:device0/name
>>>>>> gyro_3d
>>>>>> /sys/bus/iio/devices/iio:device1/name
>>>>>> dev_rotation
>>>>>> /sys/bus/iio/devices/iio:device2/name
>>>>>> als
>>>>>> /sys/bus/iio/devices/iio:device3/name
>>>>>> magn_3d
>>>>>> /sys/bus/iio/devices/iio:device4/name
>>>>>> accel_3d
>>>>>> /sys/bus/iio/devices/iio:device5/name
>>>>>> incli_3d
>>>>>>
>>>>>> are all the IIO sensors, sorry about that!
>>>>>>
>>>>>
>>>>> I was more thinking what else is in iio:device4 directory, so that we can
>>>>> see if it was initialized OK. Can you also grep the dmesg for any errors?
>>>>
>>>> Well, I just noticed the device #s are not consistent boot-to-boot, so
>>>> this time it was device0. Trimming out the directories:
>>>>
>>
>> This is correct/intended. You need to confirm "deviceX/name" each time.
>
> Got it!
>
>>>> /sys/bus/iio/devices/iio:device0/buffer
>>>> cat: /sys/bus/iio/devices/iio:device0/buffer: Is a directory
>>>> /sys/bus/iio/devices/iio:device0/dev
>>>> 250:0
>>>> /sys/bus/iio/devices/iio:device0/in_accel_hysteresis
>>>> cat: /sys/bus/iio/devices/iio:device0/in_accel_hysteresis: Invalid argument
>>>> /sys/bus/iio/devices/iio:device0/in_accel_offset
>>>> 0
>>>> /sys/bus/iio/devices/iio:device0/in_accel_sampling_frequency
>>>> 8.000000
>>>> /sys/bus/iio/devices/iio:device0/in_accel_scale
>>>> 0.009806
>>>> /sys/bus/iio/devices/iio:device0/in_accel_x_raw
>>>> 65478
>>>> /sys/bus/iio/devices/iio:device0/in_accel_y_raw
>>>> 7
>>>> /sys/bus/iio/devices/iio:device0/in_accel_z_raw
>>>> 1023
>>
>> This seems like a valid number 1023 * 0.009806 = 10,031 m/s2 but X does not.
>
> Ok...
>
>>>> /sys/bus/iio/devices/iio:device0/name
>>>> accel_3d
>>>> /sys/bus/iio/devices/iio:device0/uevent
>>>> MAJOR=250
>>>> MINOR=0
>>>> DEVNAME=iio:device0
>>>> DEVTYPE=iio_device
>>>>
>>>> Another thing I just noticed:
>>>>
>>>> /sys/bus/iio/devices/iio:device0/buffer/enable
>>>> 0
>>
>> This is buffer enable not chip enable. You can write 1 to that so it
>> will be enables
>> (echo "1" > /sys/bus/iio/devices/.../buffer/enable) and see what
>> happens. It might be
>> that it needs buffer to update properly (I haven't checked the code).
>
> Doesn't immediately seem to make a difference.
>
>>>>
>>>> The only error I'm getting consistently is:
>>>>
>>>> [    1.115327] i2c_hid i2c-ITE8396:00: error in i2c_hid_init_report
>>>> size:19 / ret_size:18
>>>>
>>>> which I don't think is relevant, but I might be wrong.
>>
>> If accel is i2c this might be a relevant error - and probe would also
>> not fail, but error would
>> repeat itself each time probably Maybe track where that line is in
>> i2c_hid and see what it
>> could mean.
>
> i2c_hid i2c-ITE8396:00: report (len=19): 12 00 5a ff ff ff ff ff ff ff
> ff ff ff ff ff ff ff ff 06
> i2c_hid i2c-ITE8396:00: error in i2c_hid_init_report size:19 / ret_size:18
>
> So it seems like the device indicates an expected return size of 18,
> but actually gives 19 bytes.
>
> I don't know anything about i2c, but i'll dig around.

Another thought I had, reading through Google results for other Yoga
laptops, the sensor device showed up in lsusb. Would I expect to see
any such device in lsusb for the Yoga 900? I only get:

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 8087:0a2b Intel Corp.
Bus 001 Device 002: ID 13d3:5664 IMC Networks
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

-Nish
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