Re: [PATCH v4 1/2] Input: Add a Kconfig to emulate KEY_SCREENLOCK with META + L

[Mario Limonciello <superm1@kernel.org>]

On 4/26/25 03:15, Pavel Machek wrote:
> On Fri 2025-04-25 11:29:48, Mario Limonciello wrote:
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> In the PC industry KEY_SCREENLOCK isn't used as frequently as it used
>> to be. Modern versions of Windows [1], GNOME and KDE support "META" + "L"
>> to lock the screen. Modern hardware [2] also sends this sequence of
>> events for keys with a silkscreen for screen lock.
>>
>> Introduced a new Kconfig option that will change KEY_SCREENLOCK when
>> emitted by driver to META + L.
> 
> Fix gnome and kde, do not break kernel...

I'm sorry; fix them to do what exactly?  Switch to KEY_SCREENLOCK?

That's going to break modern hardware lockscreen keys.  They've all 
obviously moved to META+L because that's what hardware today uses.

That's also what earlier versions of my series tried to change just 
amd-pmf over to use, but Armin Wolf said this should be done in the 
input subsystem for all drivers instead.

> 									Pavel
> 
>>   
>> +config INPUT_SCREENLOCK_EMULATION
>> +	bool "Pass KEY_SCREENLOCK as META + L"
>> +	help
>> +	  Say Y here if you want KEY_SCREENLOCK to be passed to userspace as
>> +	  META + L.
>> +
>> +	  If unsure, say Y.
>> +
>>   comment "Input Device Drivers"
>>   
>>   source "drivers/input/keyboard/Kconfig"
>> diff --git a/drivers/input/input.c b/drivers/input/input.c
>> index dfeace85c4710..983e3c0f88e5f 100644
>> --- a/drivers/input/input.c
>> +++ b/drivers/input/input.c
>> @@ -370,6 +370,13 @@ void input_handle_event(struct input_dev *dev,
>>   	}
>>   }
>>   
>> +static void handle_screenlock_as_meta_l(struct input_dev *dev, unsigned int type,
>> +					int value)
>> +{
>> +	input_handle_event(dev, type, KEY_LEFTMETA, value);
>> +	input_handle_event(dev, type, KEY_L, value);
>> +}
>> +
>>   /**
>>    * input_event() - report new input event
>>    * @dev: device that generated the event
>> @@ -392,6 +399,12 @@ void input_event(struct input_dev *dev,
>>   {
>>   	if (is_event_supported(type, dev->evbit, EV_MAX)) {
>>   		guard(spinlock_irqsave)(&dev->event_lock);
>> +#ifdef CONFIG_INPUT_SCREENLOCK_EMULATION
>> +		if (code == KEY_SCREENLOCK) {
>> +			handle_screenlock_as_meta_l(dev, type, value);
>> +			return;
>> +		}
>> +#endif
>>   		input_handle_event(dev, type, code, value);
>>   	}
>>   }
>> @@ -2134,6 +2147,13 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
>>   
>>   	switch (type) {
>>   	case EV_KEY:
>> +#ifdef CONFIG_INPUT_SCREENLOCK_EMULATION
>> +		if (code == KEY_SCREENLOCK) {
>> +			__set_bit(KEY_L, dev->keybit);
>> +			__set_bit(KEY_LEFTMETA, dev->keybit);
>> +			break;
>> +		}
>> +#endif
>>   		__set_bit(code, dev->keybit);
>>   		break;
>>   
>