From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ED1FC433F5 for ; Wed, 23 Mar 2022 22:24:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345222AbiCWWZ4 (ORCPT ); Wed, 23 Mar 2022 18:25:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345220AbiCWWZ4 (ORCPT ); Wed, 23 Mar 2022 18:25:56 -0400 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C16F8CDA1; Wed, 23 Mar 2022 15:24:25 -0700 (PDT) Received: (Authenticated sender: hadess@hadess.net) by mail.gandi.net (Postfix) with ESMTPSA id 8F6DD1BF204; Wed, 23 Mar 2022 22:24:19 +0000 (UTC) Message-ID: Subject: Re: [PATCH] HID: logitech-hidpp: support Color LED feature (8071). From: Bastien Nocera To: Filipe =?ISO-8859-1?Q?La=EDns?= , Manuel =?ISO-8859-1?Q?Sch=F6nlaub?= Cc: jikos@kernel.org, benjamin.tissoires@redhat.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 23 Mar 2022 23:24:18 +0100 In-Reply-To: <275245e8048fa124055d9ff3d10ce6562294483a.camel@riseup.net> References: <275245e8048fa124055d9ff3d10ce6562294483a.camel@riseup.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 (3.42.4-1.fc35) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Wed, 2022-03-23 at 21:22 +0000, Filipe Laíns wrote: > On Tue, 2022-03-08 at 16:50 -0700, Manuel Schönlaub wrote: > > The HID++ protocol allows to set multicolor (RGB) to a static > > color. > > Multiple of such LED zones per device are supported. > > This patch exports said LEDs so that they can be set from > > userspace. > > > > Signed-off-by: Manuel Schönlaub > > --- > >  drivers/hid/hid-logitech-hidpp.c | 188 > > +++++++++++++++++++++++++++++++ > >  1 file changed, 188 insertions(+) > > *snip* > > Hi Manuel, > > Thanks for putting this forward, although I am not sure if this is > the best way > to handle this. > > Before anything, could you elaborate a bit on what lead to you > wanting this? > > There are a couple of reasons why merging this in the kernel might be > problematic. > > 1) I don't think we will ever support the full capabilities of the > devices, so > configuration via userspace apps will always be required, and here we > are > introducing a weird line between the two. > > 2) There is already an ecosystem of userspace configuration apps, > with which > this would conflict. They might not be in the best maintenance state > due to lack > of time from the maintainers, but moving this functionality to the > kernel, which > is harder change, and harder to ship to users, will only make that > worse. There's already an API for LEDs in the kernel, why shouldn't it be used to avoid user-space needing to know how to configure Logitech, and every other brand of keyboards? systemd has code to save and restore LED status, as well as code to change the level of backlight. I can imagine that it wouldn't take much to make it aware of RGB LEDs so it handles them properly, whether it's for Logitech, or another brand of keyboards, or laptops.