linux-kernel - Re: [PATCH v2] platform/x86: Add WMI driver for Redmibook keyboard.

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Message-ID: <5e32uo4suh3mtib4tohtekwvycxgfzqcem3wwc6k6wwdxyjhpc@bt57y7vyvpmz>
Date: Tue, 5 Aug 2025 12:42:51 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Gladyshev Ilya <foxido@...ido.dev>
Cc: w_armin@....de, linux-input@...r.kernel.org, 
	nikita.nikita.krasnov@...il.com, Hans de Goede <hansg@...nel.org>, 
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, linux-kernel@...r.kernel.org, 
	platform-driver-x86@...r.kernel.org
Subject: Re: [PATCH v2] platform/x86: Add WMI driver for Redmibook keyboard.

On Tue, Jul 29, 2025 at 10:05:21PM +0300, Gladyshev Ilya wrote:
> +static void redmi_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
> +{
> +	struct redmi_wmi *data = dev_get_drvdata(&wdev->dev);
> +	int value = 1;
> +	bool autorelease = true;
> +
> +	if (obj->type != ACPI_TYPE_BUFFER) {
> +		dev_err(&wdev->dev, "Bad response type %u\n", obj->type);
> +		return;
> +	}
> +
> +	if (obj->buffer.length != 32) {
> +		dev_err(&wdev->dev, "Invalid buffer length %u\n", obj->buffer.length);
> +		return;
> +	}
> +
> +	/* For linearizability */
> +	guard(mutex)(&data->key_lock);

What is the exact purpose of this mutex? What does it protect? 

> +
> +	u32 payload = get_unaligned_le32(obj->buffer.pointer);
> +	struct key_entry *entry = sparse_keymap_entry_from_scancode(data->input_dev, payload);
> +
> +	if (!entry) {
> +		dev_dbg(&wdev->dev, "Unknown WMI event with payload %u", payload);
> +		return;
> +	}
> +
> +	/* AI key quirk */
> +	if (entry->keycode == KEY_ASSISTANT) {
> +		value = !(payload & AI_KEY_VALUE_MASK);
> +		autorelease = false;
> +	}
> +
> +	sparse_keymap_report_entry(data->input_dev, entry, value, autorelease);
> +}


Thanks.

-- 
Dmitry