Re: [PATCH] HID: i2c-hid: Disable runtime PM on Goodix touchpad

[Kai Heng Feng]

> On Jan 14, 2019, at 19:18, Jiri Kosina <jikos@xxxxxxxxxx> wrote:
> 
> On Mon, 14 Jan 2019, Kai-Heng Feng wrote:
> 
>> A Goodix touchpad doesn't work. Touching the touchpad can trigger IRQ
>> but there's no input event from HID subsystem.
>> 
>> Turns out it reports some invalid data:
>> [   22.136630] i2c_hid i2c-DELL091F:00: input: 0b 00 01 00 00 00 00 00 00 00 00
>> 
>> After some trial and error, it's another device that doesn't work well
>> with ON/SLEEP commands. Disable runtime PM to fix the issue.
> 
> Thanks, I've now applied the patch to for-5.0/upstream-fixes. I am 
> wondering though we are we seeing these at all - do other OSes not do the 
> runtime PM on i2c at all?

According to the vendor, Windows does use ON/SLEEP, but infrequently.

We can use pm_runtime_use_autosuspend() to reduce the frequency of
ON/SLEEP commands, but itâs just papering over the touchpad firmware
bug.

Kai-Heng

> 
> -- 
> Jiri Kosina
> SUSE Labs
>