From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9892138E; Fri, 19 Jan 2024 22:14:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.255.230.98 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705702479; cv=none; b=LgeM9pZAEtlMglXhSwWlHlLfKDvoLcqQsEkVdNf6VA5HEdmj4wIMUvkKh8FUAYeqdly2e01x+3o+85g+8zLR99UmngpAfu4cJX4Xq2bZj/zygiojEUtGYscd8gUqnrN+8VgxFsKRvz2oR5pngXheW8r4ZdjxrHNIZYHO0Co+g4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705702479; c=relaxed/simple; bh=tqcp8VLJ1hG12jEXoG9yMajUiGJVBaapL4MrZ2B3TzI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kmLD3jQQ+FwaD1vNuG76C6RQumOxuyBqtusytyLhP4LA2HKPXZRu+letcnCie2fXRBMNvzo0Opk2GLpGCFDfHPM/9b5DdTaHFZnTD422MjIq/TLL6yJBQiG1roBuKEy4N2n90o8EK2LKmrwp9HC8NcBSCq9L4MCdWjolwSbQ/Tc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ucw.cz; spf=pass smtp.mailfrom=ucw.cz; dkim=pass (1024-bit key) header.d=ucw.cz header.i=@ucw.cz header.b=ZkWJbbu6; arc=none smtp.client-ip=46.255.230.98 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ucw.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ucw.cz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ucw.cz header.i=@ucw.cz header.b="ZkWJbbu6" Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 71B101C0076; Fri, 19 Jan 2024 23:14:34 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1705702474; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+yAQCch9K+HPJYF16tFEjwN6QYUkinUbXhmOFLhotBI=; b=ZkWJbbu6TKig1IocluCVEyg6kj+m+tZwkENyUlGH4CSe7/ntSE6hzdUcJ6O+723NpRry/D dNJmeDFBdh77cqwXzf2/WCzSsUmB7xeAapG2mSz4ZLs5DUj1Yy8RHnwSPyvtizlnqxCUGP qmAYFH635gIQl7JDji5A7BBK/dQ7Mbo= Date: Fri, 19 Jan 2024 23:14:08 +0100 From: Pavel Machek To: Dmitry Torokhov Cc: Jani Nikula , Hans de Goede , Werner Sembach , jikos@kernel.org, Jelle van der Waa , Miguel Ojeda , Lee Jones , linux-kernel@vger.kernel.org, "dri-devel@lists.freedesktop.org" , linux-input@vger.kernel.org, ojeda@kernel.org, linux-leds@vger.kernel.org, Benjamin Tissoires Subject: Re: Implement per-key keyboard backlight as auxdisplay? Message-ID: References: <8096a042-83bd-4b9f-b633-79e86995c9b8@redhat.com> <4222268b-ff44-4b7d-bf11-e350594bbe24@redhat.com> <6bbfdd62-e663-4a45-82f4-445069a8d690@redhat.com> <87bk9hppee.fsf@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="DqqzmPOTbqCBp9No" Content-Disposition: inline In-Reply-To: --DqqzmPOTbqCBp9No Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > And while I would personally hate it, you can imagine a use case where > > you'd like a keypress to have a visual effect around the key you > > pressed. A kind of force feedback, if you will. I don't actually know, > > and correct me if I'm wrong, but feels like implementing that outside of > > the input subsystem would be non-trivial. >=20 > Actually I think it does not belong to the input subsystem as it is, > where the goal is to deliver keystrokes and gestures to userspace. The > "force feedback" kind of fits, but not really practical, again because > of lack of geometry info. It is also not really essential to be fully > and automatically handled by the kernel. So I think the best way is > > to So that's actually big question. If the common usage is "run bad apple demo on keyboard" than pretty clearly it should be display. If the common usage is "computer is asking yes/no question, so highlight yes and no buttons", then there are good arguments why input should handle that (as it does capslock led, for example). Actually I could imagine "real" use when shift / control /alt backlight would indicate sticky-shift keys for handicapped. It seems they are making mice with backlit buttons. If the main use is highlight this key whereever it is, then it should be input. But I suspect may use is just fancy colors and it should be display. Best regards, Pavel --=20 People of Russia, stop Putin before his war on Ukraine escalates. --DqqzmPOTbqCBp9No Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCZar0MAAKCRAw5/Bqldv6 8nOZAJ4+IFE/M4uAdwtp+rAqwXiKQFW5AwCfc7V3dsFCCcUTbiKDtFNWrSxtK3s= =uMxc -----END PGP SIGNATURE----- --DqqzmPOTbqCBp9No--