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

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Message-Id: <2149AEF5-ABBF-4745-89F9-7FF9719251B5@canonical.com>
Date:   Thu, 17 Jan 2019 13:02:42 +0800
From:   Kai-Heng Feng <kai.heng.feng@...onical.com>
To:     Jiri Kosina <jikos@...nel.org>
Cc:     benjamin.tissoires@...hat.com, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] HID: i2c-hid: Disable runtime PM on Goodix touchpad



> On Jan 16, 2019, at 16:21, Kai Heng Feng <kai.heng.feng@...onical.com> wrote:
> 
> 
> 
>> On Jan 14, 2019, at 19:18, Jiri Kosina <jikos@...nel.org> 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 it’s just papering over the touchpad firmware
> bug.

Goodix says the firmware needs at least 60ms to fully respond ON and
SLEEP command.

I’ll see if an 200ms autosuspend can solve all Goodix, LG and Raydium
touchpanels.

Kai-Heng

> 
> Kai-Heng
> 
>> 
>> -- 
>> Jiri Kosina
>> SUSE Labs