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Date: Tue, 6 Feb 2024 14:04:23 -0800
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Jonathan Denose <jdenose@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>, jefferymiller@google.com,
	Jonathan Denose <jdenose@google.com>,
	Raul Rangel <rrangel@chromium.org>, linux-input@vger.kernel.org
Subject: Re: [PATCH] Input: psmouse - add resync_on_resume dmi check
Message-ID: <ZcKs589qYxviC1J4@google.com>
References: <20231102075243.1.Idb37ff8043a29f607beab6440c32b9ae52525825@changeid>
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In-Reply-To: <20231102075243.1.Idb37ff8043a29f607beab6440c32b9ae52525825@changeid>

Hi Jonathan,

On Thu, Nov 02, 2023 at 07:52:47AM -0500, Jonathan Denose wrote:
> Some elantech touchpads consistently fail after resuming from
> suspend at sanity_check in elantech_packet_check_v4. This means
> the touchpad is completely unusable after suspend resume.
> 
> With different permutations of i8042 nomux, nopnp, reset, and noloop
> kernel options enabled, and with crc_enabled the touchpad fails in
> the same way.
> 
> Resyncing the touchpad after receiving the
> PACKET_UNKNOWN/PSMOUSE_BAD_DATA return code allows the touchpad to
> function correctly on resume. The touchpad fails to reconnect with
> the serio reconnect no matter how many times it retries, so this
> change skips over that retry sequence and goes directly to resync.

Why can't we do this in elantech_reconnect()? I am sure we can make it
simpler and more robust than what the generic handler is trying to do
with polling and everything.

Thanks.

-- 
Dmitry