linux-kernel - Re: [PATCH] platform/x86/intel: hid: Add DMI switches allow list

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Date:   Mon, 20 Sep 2021 18:43:05 +0000
From:   Barnabás Pőcze <pobrn@...tonmail.com>
To:     José Expósito <jose.exposito89@...il.com>
Cc:     hdegoede@...hat.com, alex.hung@...onical.com,
        mgross@...ux.intel.com, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Tobias Gurtzick <magic@...ardtales.com>
Subject: Re: [PATCH] platform/x86/intel: hid: Add DMI switches allow list

Hi


2021. szeptember 20., hétfő 18:03 keltezéssel, José Expósito írta:
> Some devices, even non convertible ones, can send incorrect
> SW_TABLET_MODE reports.
>
> Add an allow list and accept such reports only from devices in it.
>
> Bug reported for Dell XPS 17 9710 on:
> https://gitlab.freedesktop.org/libinput/libinput/-/issues/662
>
> Reported-by: Tobias Gurtzick <magic@...ardtales.com>
> Suggested-by: Hans de Goede <hdegoede@...hat.com>
> Tested-by: Tobias Gurtzick <magic@...ardtales.com>
> Signed-off-by: José Expósito <jose.exposito89@...il.com>
> ---
>  drivers/platform/x86/intel/hid.c | 33 +++++++++++++++++++++++++++-----
>  1 file changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/hid.c b/drivers/platform/x86/intel/hid.c
> index a33a5826e81a..24d26336e39a 100644
> --- a/drivers/platform/x86/intel/hid.c
> +++ b/drivers/platform/x86/intel/hid.c
> @@ -118,6 +118,24 @@ static const struct dmi_system_id dmi_vgbs_allow_list[] = {
>  	{ }
>  };
>
> +/*
> + * Some devices, even non convertible ones, can send incorrect SW_TABLET_MODE
> + * reports. Accept such reports only from devices in this list.
> + */
> +static const struct dmi_system_id dmi_switches_auto_add_allow_list[] = {
> +	{
> +		.matches = {
> +			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
> +		},
> +	},
> +	{} /* Array terminator */
> +};
> +
>  struct intel_hid_priv {
>  	struct input_dev *input_dev;
>  	struct input_dev *array;
> @@ -455,11 +473,16 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
>  	 *
>  	 * See dual_accel_detect.h for more info on the dual_accel check.
>  	 */
> -	if (!priv->switches && !priv->dual_accel && (event == 0xcc || event == 0xcd)) {
> -		dev_info(&device->dev, "switch event received, enable switches supports\n");
> -		err = intel_hid_switches_setup(device);
> -		if (err)
> -			pr_err("Failed to setup Intel HID switches\n");
> +	if (event == 0xcc || event == 0xcd) {
> +		if (!dmi_check_system(dmi_switches_auto_add_allow_list))
> +			return;

I think you should not check it every time. Maybe add a `bool` member
to `struct intel_hid_priv`. Or maybe better: rename `dual_accel` to something like
`autodetect_switch` and initialize it with `!dual_accel_detect() && dmi_check_system(...)`.


> +
> +		if (!priv->switches && !priv->dual_accel) {
> +			dev_info(&device->dev, "switch event received, enable switches supports\n");
> +			err = intel_hid_switches_setup(device);
> +			if (err)
> +				pr_err("Failed to setup Intel HID switches\n");
> +		}
>  	}
>
>  	if (priv->wakeup_mode) {
> --
> 2.25.1
>
>


Regards,
Barnabás Pőcze