From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH] pwm: mxs: set pwm_chip can_sleep flag Date: Wed, 9 Apr 2014 01:16:54 +0200 Message-ID: <20140408231654.GA13898@piout.net> References: <1396956597-26159-1-git-send-email-shawn.guo@freescale.com> <5343FDD3.3070308@i2se.com> <20140408141832.GA8861@piout.net> <53442997.70209@i2se.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from top.free-electrons.com ([176.31.233.9]:56676 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756739AbaDHXQ5 (ORCPT ); Tue, 8 Apr 2014 19:16:57 -0400 Content-Disposition: inline In-Reply-To: <53442997.70209@i2se.com> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Stefan Wahren Cc: Shawn Guo , linux-pwm@vger.kernel.org, Thierry Reding , linux-arm-kernel@lists.infradead.org, Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Hi, On 08/04/2014 at 18:53:43 +0200, Stefan Wahren wrote : > i applied these 5 patches, but it doesn't fix the problem. > > Here are my results for the pwm driver led on i.MX28: > > version | trigger: none | trigger: heartbeat > ----------------------------------------------------------------------------- > 3.14 | OK | NOT OK (WARNING, LED > permanent on) > + shawn's patch | OK | NOT OK (LED > permanent on) > + russell's patches | OK | NOT OK (LED > permanent on) > + active-low | NOT OK (inverse logic) | NOT OK (LED > permanent on) > > Russell's patches work as expected, but have not influence on the heartbeat. > Yeah, I got it wrong or explained badly. So, if without Russell's patches, your pwm is not inversed, then you would have to set active_low and inverse the pwm. If it was inversed, then you'll have to set active_low and let the pwm with the normal polarity. I know this is a bit contrived but this was exactly my point why we shouldn't call it active_low. Can you try to switch the polarity when setting active_low ? I'm not home, else I'll try on my i.mx28 boards... -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com