Re: [PATCH] platform/x86: ideapad-laptop: Stop sending KEY_TOUCHPAD_TOGGLE

[Maxim Mikityanskiy <maxtram95@gmail.com>]

On Thu, 30 Mar 2023 at 21:46:44 +0200, Hans de Goede wrote:
> Commit 5829f8a897e4 ("platform/x86: ideapad-laptop: Send
> KEY_TOUCHPAD_TOGGLE on some models") made ideapad-laptop send
> KEY_TOUCHPAD_TOGGLE when we receive an ACPI notify with VPC event bit 5 set
> and the touchpad-state has not been changed by the EC itself already.
> 
> This was done under the assumption that this would be good to do to make
> the touchpad-toggle hotkey work on newer models where the EC does not
> toggle the touchpad on/off itself (because it is not routed through
> the PS/2 controller, but uses I2C).
> 
> But it turns out that at least some models, e.g. the Yoga 7-15ITL5 the EC
> triggers an ACPI notify with VPC event bit 5 set on resume, which would
> now cause a spurious KEY_TOUCHPAD_TOGGLE on resume to which the desktop
> environment responds by disabling the touchpad in software, breaking
> the touchpad (until manually re-enabled) on resume.

Oh gosh, the touchpad toggle on Ideapads is so much broken, I wonder how
the Windows driver deals with all this variety of different behaviors
(unless it's broken too :D).

I'll test the patch on Z570, but as I see, it shouldn't change anything
for Z570.

> It was never confirmed that sending KEY_TOUCHPAD_TOGGLE actually improves
> things on new models and at least some new models like the Yoga 7-15ITL5
> don't have a touchpad on/off toggle hotkey at all, while still sending
> ACPI notify events with VPC event bit 5 set.
> 
> So it seems best to revert the change to send KEY_TOUCHPAD_TOGGLE when
> receiving an ACPI notify events with VPC event bit 5 and the touchpad
> state as reported by the EC has not changed.
> 
> Note this is not a full revert the code to cache the last EC touchpad
> state is kept to avoid sending spurious KEY_TOUCHPAD_ON / _OFF events
> on resume.
> 
> Fixes: 5829f8a897e4 ("platform/x86: ideapad-laptop: Send KEY_TOUCHPAD_TOGGLE on some models")
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217234
> Cc: stable@vger.kernel.org
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/platform/x86/ideapad-laptop.c | 23 ++++++++++-------------
>  1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
> index b5ef3452da1f..35c63cce0479 100644
> --- a/drivers/platform/x86/ideapad-laptop.c
> +++ b/drivers/platform/x86/ideapad-laptop.c
> @@ -1170,7 +1170,6 @@ static const struct key_entry ideapad_keymap[] = {
>  	{ KE_KEY,  65, { KEY_PROG4 } },
>  	{ KE_KEY,  66, { KEY_TOUCHPAD_OFF } },
>  	{ KE_KEY,  67, { KEY_TOUCHPAD_ON } },
> -	{ KE_KEY,  68, { KEY_TOUCHPAD_TOGGLE } },
>  	{ KE_KEY, 128, { KEY_ESC } },
>  
>  	/*
> @@ -1526,18 +1525,16 @@ static void ideapad_sync_touchpad_state(struct ideapad_private *priv, bool send_
>  	if (priv->features.ctrl_ps2_aux_port)
>  		i8042_command(&param, value ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE);
>  
> -	if (send_events) {
> -		/*
> -		 * On older models the EC controls the touchpad and toggles it
> -		 * on/off itself, in this case we report KEY_TOUCHPAD_ON/_OFF.
> -		 * If the EC did not toggle, report KEY_TOUCHPAD_TOGGLE.
> -		 */
> -		if (value != priv->r_touchpad_val) {
> -			ideapad_input_report(priv, value ? 67 : 66);
> -			sysfs_notify(&priv->platform_device->dev.kobj, NULL, "touchpad");
> -		} else {
> -			ideapad_input_report(priv, 68);
> -		}
> +	/*
> +	 * On older models the EC controls the touchpad and toggles it on/off
> +	 * itself, in this case we report KEY_TOUCHPAD_ON/_OFF. Some models do
> +	 * an acpi-notify with VPC bit 5 set on resume, so this function get
> +	 * called with send_events=true on every resume. Therefor if the EC did
> +	 * not toggle, do nothing to avoid sending spurious KEY_TOUCHPAD_TOGGLE.
> +	 */
> +	if (send_events && value != priv->r_touchpad_val) {
> +		ideapad_input_report(priv, value ? 67 : 66);
> +		sysfs_notify(&priv->platform_device->dev.kobj, NULL, "touchpad");
>  	}
>  
>  	priv->r_touchpad_val = value;
> -- 
> 2.39.1
>