Re: Why hid-sensor-hub's IIO doesn't work properly in >= 4.3 (possibly badly bisected)

On Thu, 2017-02-02 at 00:38 +0100, Rafael J. Wysocki wrote:

+ Srinivas

On Tuesday, January 31, 2017 02:37:43 PM Bastien Nocera wrote:

quoted

Hey Rafael,

On Fri, 2017-01-27 at 00:07 +0100, Rafael J. Wysocki wrote:

quoted

On Thu, Jan 26, 2017 at 4:15 PM, Bastien Nocera <hadess@hadess.ne
t>
wrote:

quoted

On Fri, 2017-01-20 at 16:52 +0100, Bastien Nocera wrote:

quoted

Hey,

TLDR:
# first bad commit:
[50ba22479c324c0d9dc8134d519dcba92d83a8a7]
Merge
back earlier ACPI PM material for v4.3.

hid-sensor-hub devices only start sending events through the
IIO
trigger after a suspend/resume cycle.

Srinivas, does it sound like anything familiar to you?

I guess this is related to
https://github.com/hadess/iio-sensor-proxy/issues/82

There is some race between user space and iio. So the driver powerup
never gets called back to power a hub during system boot. So the
workaround was to add to systemd unit file for iio-sensor-proxy 
[Unit]
After=multi-user.target

Something changed timings in the kernel, which triggered this issue.
I never got chance to root cause this.

Thanks,
Srinivas