Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965526AbbD0WXl (ORCPT ); Mon, 27 Apr 2015 18:23:41 -0400 Received: from smtp8.mail.ru ([94.100.181.96]:58760 "EHLO smtp8.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965187AbbD0WXi (ORCPT ); Mon, 27 Apr 2015 18:23:38 -0400 X-Greylist: delayed 18923 seconds by postgrey-1.27 at vger.kernel.org; Mon, 27 Apr 2015 18:23:37 EDT Message-ID: <553EB6CB.6070104@list.ru> Date: Tue, 28 Apr 2015 01:23:07 +0300 From: Stas Sergeev User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Pavel Machek CC: linux-leds@vger.kernel.org, Linux kernel , Stas Sergeev Subject: Re: [PATCH v2 0/3] leds: blink resolution improvements References: <553E6CF5.4030601@list.ru> <20150427205441.GB1301@xo-6d-61-c0.localdomain> In-Reply-To: <20150427205441.GB1301@xo-6d-61-c0.localdomain> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam: Not detected X-Mras: Ok Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1077 Lines: 23 27.04.2015 23:54, Pavel Machek пишет: > Hi! > >> The following patches improve the precision of led >> timer trigger and add the delay unit control. >> That allows to make PWM brightness control with timer >> trigger. > Are you sure that is good idea? Doing LED pwm with main cpu is quite harsh... > > We already have "brightness" for... well... brightness level. Btw, your concern can also be addressed in a simple way: just remove the "brightness" attribute in "timer" mode if the HW does not support brightness. In some modes you still need brightness to write either 0 or 255, but in timer mode it seems absolutely redundant without a HW implementation. I'd like to create the patch to conditionally disable the brightness attr in "timer" mode, but I wonder if the change will have the unexpected compatibility problems... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/