Re: [PATCH] Add keycode to Dell G-Mode key

[Marcos Alano <marcoshalano@gmail.com>]

On 28/04/2025 22:44, Dmitry Torokhov wrote:
> Hi Marcos,
>
Hi Dmitry,

> 
> Could you please tell me more about the performance mode? What does it
> do and how it differs from normal (?) mode, and also whether it is
> something Dell-specific or whether it is also available on other
> devices.
This is the performance mode related to power consumption. I think 
kernel calls this "performance profile".
When you don't need to save power, you can improve performance by 
increasing the clock.
For some machines this G-Mode is already enabled when selecting the 
performance profile: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/platform/x86/dell/alienware-wmi-wmax.c#n51
> 
> What input device emits this key code? atkbd? Something
> platform-specific?
atkbd, I think. It parts of the regular keyboard, scan code 0x68.
> 
> My inclination would be to use KEY_VENDOR for this functionality, at
> least for now, as the feature seems very vendor-specific.
Yes, it's very vendor-specific. Dell uses for some Dell and Alienware 
machines.
I don't think we can use KEY_VENDOR because that could have another 
KEY_VENDOR in the keyboard, I think. The idea is to be a very exclusive 
keycode, that when detected, it would indicate that you want to activate 
the "performance profile" and don't do anything else.
An alternative would be create a new keycode called KEY_PERF or 
KEY_PERF_MODE. That would activate the performance profile, but it would 
be vendor-agnostic and if any other vendors, like HP, Lenovo, Acer, etc. 
want to implement the same feature, that would be possible.
> 
> Thanks.
> 
No, thank you. Please let me know what you think. :)

-- 
Marcos Alano