linux-kernel - Re: [PATCH v2 0/3] HID: i2c-hid: Probe and wake device with HID descriptor fetch

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Date: Wed, 24 Apr 2024 12:34:30 +0200
From: Łukasz Majczak <lma@...omium.org>
To: Kenny Levinsen <kl@...wtf>
Cc: Jiri Kosina <jikos@...nel.org>, Dmitry Torokhov <dtor@...omium.org>, 
	Benjamin Tissoires <benjamin.tissoires@...hat.com>, Douglas Anderson <dianders@...omium.org>, 
	Hans de Goede <hdegoede@...hat.com>, Maxime Ripard <mripard@...nel.org>, 
	Kai-Heng Feng <kai.heng.feng@...onical.com>, Johan Hovold <johan+linaro@...nel.org>, 
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Radoslaw Biernacki <rad@...omium.org>
Subject: Re: [PATCH v2 0/3] HID: i2c-hid: Probe and wake device with HID
 descriptor fetch

On Tue, Apr 23, 2024 at 2:26 PM Kenny Levinsen <kl@...wtf> wrote:
>
> This revises my previous patch[0] to add the sleep STM chips seem to
> require as per discussion on the original patch from Lukasz and
> Radoslaw[1]. I had initially tried without as it had not previously been
> needed in the similar logic in our resume path, but it would appear that
> this was simply luck as the affected device was woken up in that case by
> "noise" from other sources.
>
> To reiterate, the idea is to add the retry that Lukasz and Radoslaw
> discovered was necessary, but do away with the dummy smbus probe and
> instead just let HID descriptor fetch retry as needed, aligning more
> with the existing retry logic used after resume while saving some noise
> on the bus and speeding up initialization a tiny bit.
>
> I added Co-developed-by tags, I hope that's appropriate. We should await
> an ACK from Lukasz on it fixing their hardware quirk.
>
> [0]: https://lore.kernel.org/all/20240415170517.18780-1-kl@kl.wtf/
> [1]: https://lore.kernel.org/all/CAE5UKNqPA4SnnXyaB7Hwk0kcKMMQ_DUuxogDphnnvSGP8g1nAQ@mail.gmail.com/
>
Hi Kenny,

Your solution works as it should - I have tested it on my Eve with
enabled debugs and
the retries works as expected with power-on, reboot and suspend/resume paths.

I have also disabled cros_ec_i2c driver to be 100% sure it doesn't do
any i2c transactions on the bus
and again the touchpad initialized successfully (with a retry) on all paths.

So you can add:
Tested-by: Lukasz Majczak <lma@...omium.org>
Reviewed-by: Lukasz Majczak <lma@...omium.org>

Thank you Kenny for your work :)

Best regards,
Lukasz