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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E979C2BC11 for ; Fri, 11 Sep 2020 17:38:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2520C221E7 for ; Fri, 11 Sep 2020 17:38:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726009AbgIKMp6 (ORCPT ); Fri, 11 Sep 2020 08:45:58 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:57652 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725951AbgIKMnT (ORCPT ); Fri, 11 Sep 2020 08:43:19 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kGiOI-00EE62-Lc; Fri, 11 Sep 2020 14:42:58 +0200 Date: Fri, 11 Sep 2020 14:42:58 +0200 From: Andrew Lunn To: Matthias Schiffer Cc: Marek =?iso-8859-1?Q?Beh=FAn?= , Pavel Machek , netdev@vger.kernel.org, linux-leds@vger.kernel.org, Dan Murphy , =?utf-8?Q?Ond=C5=99ej?= Jirman , Russell King , linux-kernel@vger.kernel.org, "David S. Miller" Subject: Re: [PATCH net-next + leds v2 6/7] net: phy: marvell: add support for LEDs controlled by Marvell PHYs Message-ID: <20200911124258.GB3390477@lunn.ch> References: <20200909162552.11032-1-marek.behun@nic.cz> <20200909162552.11032-7-marek.behun@nic.cz> <20200910122341.GC7907@duo.ucw.cz> <20200910131541.GD3316362@lunn.ch> <20200910161522.3cf3ad63@dellmb.labs.office.nic.cz> <20200910150040.GB3354160@lunn.ch> <3d4dd05f2597c66fb429580095eed91c2b3be76a.camel@ew.tq-group.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3d4dd05f2597c66fb429580095eed91c2b3be76a.camel@ew.tq-group.com> Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org > - Do all PHYs support manual setting of the LED level, or are the PHYs > that can only work with HW triggers? There are PHYs with do not have simple on/off. > - Is setting PHY registers always efficiently possible, or should SW > triggers be avoided in certain cases? I'm thinking about setups like > mdio-gpio. I guess this can only become an issue for triggers that > blink. There are uses cases where not using software frequently writing registers would be good. PTP time stamping is one, where the extra jitter can reduce the accuracy of the clock. I also think activity blinking in software is unlikely to be accepted. Nothing extra is allowed in the hot path, when you can be dealing with a million or more packets per second. So i would say limit software fallback to link and speed, and don't assume that is even possible depending on the hardware. Andrew