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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49A1CC433F5 for ; Mon, 27 Sep 2021 18:48:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18CFF60E09 for ; Mon, 27 Sep 2021 18:48:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236312AbhI0SuH (ORCPT ); Mon, 27 Sep 2021 14:50:07 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:58582 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234211AbhI0SuH (ORCPT ); Mon, 27 Sep 2021 14:50:07 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1632768507; 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=8BGlrwhl0ZM/cvrS5DhwVcIKaCB7N0GdYz6xRTCEVns=; b=n5RI0ORWCst6lQMymCYc+7raQfuNYV/eoQS5AuChy1W6Sh8YgJQJ4+6QM/8n85dkCXvoVC peLzecec9W+Rqd7TsxVubSf83O/XJH0yhGiZXbmGRqUc22QuOo0PmWBxO37fi7x8H1a88w ZFNv8Fzb/LNdSwpMpyJ6wtRgK706HkMQw+FofL59r5vLmMv3o5b17g66BmsE5kti/r2Eke v1BaiFas6QKd2neUBfqC0hgFOR7QbCAwMRnUI7Oqxa5BaxRPLCGEj847XrgHRDq4GDJDml WpRxXYgD29XGHQiCHkvcAXELbYIo3GLOzZ6+9avgWKxJJa0AGKCcgGXRDBvrvg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1632768507; 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=8BGlrwhl0ZM/cvrS5DhwVcIKaCB7N0GdYz6xRTCEVns=; b=WTlRnmTR9h6M7hCpeKsaFgq5It0sQK31i4IP1rCTGQwFbHtaaSuUg/4pi0Hbk5cejCJcvw qSfqOF9Ot/IR59DA== To: Pavel Machek Cc: Sebastian Andrzej Siewior , johannes.berg@intel.com, linux-leds@vger.kernel.org Subject: Re: [PATCH] leds: trigger: Disable CPU trigger on PREEMPT_RT In-Reply-To: <20210927154451.GA17112@duo.ucw.cz> References: <20210924111501.m57cwwn7ahiyxxdd@linutronix.de> <20210927142345.GB18276@duo.ucw.cz> <87wnn2av6h.ffs@tglx> <20210927154451.GA17112@duo.ucw.cz> Date: Mon, 27 Sep 2021 20:48:27 +0200 Message-ID: <87mtnxc0sk.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Pavel, On Mon, Sep 27 2021 at 17:44, Pavel Machek wrote: > On Mon 2021-09-27 17:35:02, Thomas Gleixner wrote: >> Disabling stuff which is not working well with RT is very much a >> solution in order to make progress. >> >> We have surely more essential problems to solve than making leds blink >> and if anyone cares enough about them, then this can be worked on in >> parallel. That has been disabled on RT for ever and so far nobody >> complained or cared enough about it. > > Would you mind reading and responding to the rest of the email? Sure. As Sebastian said, its not only the rwlock in led-triggers, it's the whole call chain down to led_cdec->set_brightness() with a gazillion of drivers and quite some of them take locks. > I'm not applying this. That's fine with me, I just move arch/arm RT support to the very end of my todo list then. Thanks for your support! tglx