linux-kernel - Re: [PATCH] platform/x86: ideapad-laptop: Disable touchpad

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Message-ID: <bade32f9-594c-3efd-d6da-ea6a4a433948@redhat.com>
Date:   Tue, 18 Oct 2022 09:48:16 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Manyi Li <limanyi@...ontech.com>, ike.pan@...onical.com,
        markgross@...nel.org
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] platform/x86: ideapad-laptop: Disable touchpad_switch

Hi,

On 10/18/22 08:14, Manyi Li wrote:
> Ideapads for "Lenovo Yoga 3 Pro 1370" and "ZhaoYang K4e-IML" do not
> use EC to switch touchpad.
> 
> Reading VPCCMD_R_TOUCHPAD will return zero thus touchpad may be blocked
> unexpectedly.
> 
> Signed-off-by: Manyi Li <limanyi@...ontech.com>
> ---
>  drivers/platform/x86/ideapad-laptop.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
> index abd0c81d62c4..20b8a94934b4 100644
> --- a/drivers/platform/x86/ideapad-laptop.c
> +++ b/drivers/platform/x86/ideapad-laptop.c
> @@ -1533,6 +1533,24 @@ static const struct dmi_system_id hw_rfkill_list[] = {
>  	{}
>  };
>  
> +static const struct dmi_system_id no_touchpad_switch_list[] = {
> +	{
> +	.ident = "Lenovo Yoga 3 Pro 1370",
> +	.matches = {
> +		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> +		DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo YOGA 3"),
> +		},
> +	},
> +	{
> +	.ident = "ZhaoYang K4e-IML",
> +	.matches = {
> +		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> +		DMI_MATCH(DMI_PRODUCT_VERSION, "ZhaoYang K4e-IML"),
> +		},
> +	},
> +	{}
> +};
> +
>  static void ideapad_check_features(struct ideapad_private *priv)
>  {
>  	acpi_handle handle = priv->adev->handle;
> @@ -1542,6 +1560,7 @@ static void ideapad_check_features(struct ideapad_private *priv)
>  
>  	/* Most ideapads with ELAN0634 touchpad don't use EC touchpad switch */
>  	priv->features.touchpad_ctrl_via_ec = !acpi_dev_present("ELAN0634", NULL, -1);
> +	priv->features.touchpad_ctrl_via_ec = !dmi_check_system(no_touchpad_switch_list);

This needs to be:

	priv->features.touchpad_ctrl_via_ec =
		!acpi_dev_present("ELAN0634", NULL, -1) &&
		!dmi_check_system(no_touchpad_switch_list);

Otherwise you over overriding the results of the ELAN0634 check. Also I wonder if there
is not a better way to check for this (for both cases) ?

Is the touchpad on these devices perhaps connected over I2C ? Maybe we need to figure
out a way to check for that.

Regards,

Hans



>  
>  	if (!read_ec_data(handle, VPCCMD_R_FAN, &val))
>  		priv->features.fan_mode = true;