Received-SPF: pass (google.com: domain of linux-kernel+bounces-45116-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Message-ID: <1bc6d6f0-a13d-4148-80cb-9c13dec7ed32@redhat.com>
Date: Tue, 30 Jan 2024 19:35:21 +0100
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Implement per-key keyboard backlight as auxdisplay?
To: Werner Sembach <wse@tuxedocomputers.com>, Pavel Machek <pavel@ucw.cz>
Cc: Jani Nikula <jani.nikula@linux.intel.com>, jikos@kernel.org,
 Jelle van der Waa <jelle@vdwaa.nl>,
 Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>, Lee Jones <lee@kernel.org>,
 linux-kernel@vger.kernel.org,
 "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
 linux-input@vger.kernel.org, ojeda@kernel.org, linux-leds@vger.kernel.org
References: <aac81702-df1e-43a2-bfe9-28e9cb8d2282@tuxedocomputers.com>
 <ZSmg4tqXiYiX18K/@duo.ucw.cz>
 <CANiq72mfP+dOLFR352O0UNVF8m8yTi_VmOY1zzQdTBjPWCRowg@mail.gmail.com>
 <87sf61bm8t.fsf@intel.com> <ZVvHG/Q+V6kCnfKZ@duo.ucw.cz>
 <f4137e34-c7fb-4f21-bc93-1496cbf61fdf@tuxedocomputers.com>
 <8096a042-83bd-4b9f-b633-79e86995c9b8@redhat.com>
 <f416fbca-589b-4f6a-aad6-323b66398273@tuxedocomputers.com>
 <4222268b-ff44-4b7d-bf11-e350594bbe24@redhat.com>
 <ac02143c-d417-49e5-9c6e-150cbda71ba7@tuxedocomputers.com>
 <ZaljwLe7P+dXHEHb@duo.ucw.cz>
 <6bbfdd62-e663-4a45-82f4-445069a8d690@redhat.com>
 <0cdb78b1-7763-4bb6-9582-d70577781e61@tuxedocomputers.com>
 <7228f2c6-fbdd-4e19-b703-103b8535d77d@redhat.com>
 <730bead8-6e1d-4d21-90d2-4ee73155887a@tuxedocomputers.com>
 <952409e1-2f0e-4d7a-a7a9-3b78f2eafec7@redhat.com>
 <9851a06d-956e-4b57-be63-e10ff1fce8b4@tuxedocomputers.com>
Content-Language: en-US, nl
From: Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <9851a06d-956e-4b57-be63-e10ff1fce8b4@tuxedocomputers.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

Hi,

On 1/30/24 19:09, Werner Sembach wrote:
> Hi Hans,
> 
> resend because Thunderbird htmlified the mail :/

I use thunderbird too. If you right click on the server name
and then go to "Settings" -> "Composition & Addressing"
and then uncheck "Compose messages in HTML format"
I think that should do the trick.

> Am 30.01.24 um 18:10 schrieb Hans de Goede:
>> Hi Werner,
>>
>> On 1/30/24 12:12, Werner Sembach wrote:
>>> Hi Hans,
>>>
>>> Am 29.01.24 um 14:24 schrieb Hans de Goede:
> <snip>
>>> I think that are mostly external keyboards, so in theory a possible cut could also between built-in and external devices.
>> IMHO it would be better to limit /dev/rgbledstring use to only
>> cases where direct userspace control is not possible and thus
>> have the cut be based on whether direct userspace control
>> (e.g. /dev/hidraw access) is possible or not.
> 
> Ack
> 
> <snip>
> 
>>> So also no basic driver? Or still the concept from before with a basic 1 zone only driver via leds subsystem to have something working, but it is unregistered by userspace, if open rgb wants to take over for fine granular support?
>> Ah good point, no I think that a basic driver just for kbd backlight
>> brightness support which works with the standard desktop environment
>> controls for this makes sense.
>>
>> Combined with some mechanism for e.g. openrgb to fully take over
>> control as discussed. It is probably a good idea to file a separate
>> issue with the openrgb project to discuss the takeover API.
> 
> I think the OpenRGB maintainers are pretty flexible at that point, after all it's similar to enable commands a lot of rgb devices need anyway. I would include it in a full api proposal.

Ack.

> On this note: Any particular reason you suggested an ioctl interface instead of a sysfs one? (Open question as, for example, I have no idea what performance implications both have)

sysfs APIs typically have a one file per setting approach,
so for effects with speed and multiple-color settings you
would need a whole bunch of different files and then you
would either need to immediately apply every setting,
needing multiple writes to the hw for a single effect
update, or have some sort of "commit" sysfs attribute.

With ioctls you can simply provide all the settings
in one call, which is why I suggested using ioctls.

Regards,

Hans