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 26A63ECAAA1 for ; Sun, 30 Oct 2022 20:15:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbiJ3UPd (ORCPT ); Sun, 30 Oct 2022 16:15:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbiJ3UPb (ORCPT ); Sun, 30 Oct 2022 16:15:31 -0400 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 594CAA185; Sun, 30 Oct 2022 13:15:30 -0700 (PDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 81C001C0049; Sun, 30 Oct 2022 21:15:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1667160928; 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=SRUdneXHxh/Cv6fvYSjs07wKwz7JXwgYVVxDoXQty8s=; b=eqHxQA1emI0dt09Uf566QBHKNMWni+R6zQZbJvKogxPJquSKsnd+IPfrLMxFT7V//xgQmv luoikPnbPz2F2gcOyhOL5MOvA4CutdR6miiuiGneuzQO6zTG6VGBVcw9QtlKF03rYdgPL7 YLddMeumTV/qvZ2GZyxlBBHz7nS8WoY= Date: Sun, 30 Oct 2022 21:15:27 +0100 From: Pavel Machek To: Arseniy Krasnov Cc: "linux-kernel@vger.kernel.org" , "linux-leds@vger.kernel.org" , kernel Subject: Re: [RFC PATCH v1 1/1] leds: support to use own workqueue for each LED Message-ID: <20221030201527.GA23195@duo.ucw.cz> References: <9a0a70a8-0886-1115-6151-72d2cba842cf@sberdevices.ru> <33d05330-7c52-e873-bf32-209d40c77632@sberdevices.ru> <20221030122029.GA8017@duo.ucw.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ZGiS0Q5IWpPtfppv" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ZGiS0Q5IWpPtfppv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > >> This allows to set own workqueue for each LED. This may be useful, bec= ause > >> default 'system_wq' does not guarantee execution order of each work_st= ruct, > >> thus for several brightness update requests (for multiple leds), real > >> brightness switch could be in random order. > >=20 > > So.. what? > >=20 > > Even if execution order is switched, human eye will not be able to > > tell the difference. > Hello, >=20 > Problem arises on one of our boards where we have 14 triples of leds(each > triple contains R G B). Test case is to play complex animation on all led= s: > smooth switch from on RGB state to another. Sometimes there are glitches = in > this process - divergence from expectable RGB state. We fixed this by usi= ng > ordered workqueue. Are there other solutions possible? Like batch and always apply _all_ the updates you have queued from your the worker code? Best regards, Pavel --=20 People of Russia, stop Putin before his war on Ukraine escalates. --ZGiS0Q5IWpPtfppv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCY17bXwAKCRAw5/Bqldv6 8nHqAJ460FAvTohZFx62OjyLkAZzcTBWuwCdEuMPpqEQExkcrAlv3eJJ2vF6Yx4= =fMSI -----END PGP SIGNATURE----- --ZGiS0Q5IWpPtfppv--