Re: [PATCH 0/1] platform/x86/tuxedo: Add virtual LampArray for TUXEDO NB04

[Pavel Machek <pavel@ucw.cz>]

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On Fri 2024-09-27 18:08:52, Benjamin Tissoires wrote:
> On Sep 26 2024, Werner Sembach wrote:
> > Hi,
> > took some time but now a first working draft of the suggested new way of
> > handling per-key RGB keyboard backlights is finished. See:
> > https://lore.kernel.org/all/1fb08a74-62c7-4d0c-ba5d-648e23082dcb@tuxedocomputers.com/
> > First time for me sending a whole new driver to the LKML, so please excuse
> > mistakes I might have made.
> > 
> > Known bugs:
> > - The device has a lightbar which is currently not implemented and
> >   therefore stuck to blue once the first backlight control command is send.
> > 
> > What is still missing:
> > - The leds fallback
> > - Lightbar control
> > 
> > Some general noob questions:
> > 
> > Initially I though it would be nice to have 2 modules, one jsut being the
> > wmi initialization and utility stuff and one just being the backlight logic
> > stuff, being loaded automatically via module_alias, but that would still
> > require me to create the virtual hid device during the wmi_ab probe, and
> > that already needs the ll_driver, so i guess I have to do it statically
> > like i did now?
> > Or in other words: I would have liked to have a module dependency graph
> > like this:
> >     tuxedo_nb04_lamp_array depends on tuxedo_nb04_platform (combining *_wmi_init and *_wmi_utility)
> > but if i currently split it into modules i would get this:
> >     tuxedo_nb04_wmi_ab_init dpends on tuxedo_nb04_wmi_ab_lamp_array depends on tuxedo_nb04_wmi_utility
> 
> On more general question to you: how much confident are you about your
> LampArray implementation?
> 
> If you still need to add/fix stuff in it, I would advise you to have a
> simple HID device, with bare minimum functionality, and then add the
> LampArray functionality on top through HID-BPF. This way you can fix
> LampArray out of band with the kernel, while having a more stable kernel
> module. This should be possible with v6.11+.
> 
> Another solution is to still have your wmi-to-hid module, and then a
> HID kernel module in drivers/hid that supports LampArray.
> 
> But I would strongly suggest while you are figuring out the userspace
> part to stick to HID-BPF, and then once you are happy we can move to a
> full kernel module.

What about creating real kernel driver with real interface to
userland, instead? My preference would be treating this as a display,
but nearly anything is better than _this_.

Best regards,
								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

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