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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 93081C43331 for ; Fri, 3 Apr 2020 23:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EDD320721 for ; Fri, 3 Apr 2020 23:50:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UhWO1YFI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726300AbgDCXuT (ORCPT ); Fri, 3 Apr 2020 19:50:19 -0400 Received: from mail-oi1-f196.google.com ([209.85.167.196]:36779 "EHLO mail-oi1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725268AbgDCXuS (ORCPT ); Fri, 3 Apr 2020 19:50:18 -0400 Received: by mail-oi1-f196.google.com with SMTP id k18so7784572oib.3; Fri, 03 Apr 2020 16:50:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xXdcqrAdiSxima2XcozxNqRPj0pqP4ss3zDOgQD4mx4=; b=UhWO1YFIfHTznbNhajAUv64cFNintquNZGXcJ8Z2HYUQmri9FqbJuNYOrtuovUsWht jQZt+yRDjEnZ5cmOVtEgCCzlffDTWgcyiOTsnFIGRKKiBoraP/AY6MMPLWte78FNyaEz 6HUWNmq82a6rQNPtKaBezY3U64n0P24Zc4zoiLHTv5tJffks9Dt/+lsMAH70AhcReeL7 Tp5kZeK9Blv0L1Ne/0BpGfQOCToBQAJAmtxe7F9/b2BE8ihPsb6b/OxIHgwYExLEM60w J4b2EpI6g4plsTWM3xHEplCuePabooOEneBg2ocge7f2HVf/m7mD3PAwUJjDiyKbDSIK 3urw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xXdcqrAdiSxima2XcozxNqRPj0pqP4ss3zDOgQD4mx4=; b=L1+0vnJD3jQjybXrn/4iRcGgaS6GcuHFQtOwlGf4vyaVO79+44QJDl2dg3E4+cSSdm 1oSQsxyJgnbIRiTmory19f6x6UVijpAuJFItK2IsFfsDfLQTiPkX3XNopHwCfc0yuOv6 HXZKkxkUJrCCLGdFnPkWAPQT0QGrT60xdP9tR4La/Hi+5DTEp8OE9Mv5ZeUSjck7VSau xZ+fZ8xXaLTH8x3XreV3GHdYHxXLwfGcKS3XC/0JeJ1vcWjd2jQweVroVZAbwtORzQJx hDF6odrTpSKkkBvjo0CUXOTnm2iqTFMlXaMKm7fIghZDR18seUvih69WpU7m9hhvrL2m UNFQ== X-Gm-Message-State: AGi0Pub0UpLUI4Dh128K8jT/EZ4WSTAzNFAs/a4GsOUyJpNdME0zDF4R p5eN0FraDwkwFO3I10e6QG0i7ifvQ9+n/fLei7uf/A== X-Google-Smtp-Source: APiQypJV3OB/eUwke7DNWeBdA2bwA1uZVW8eSCd+syKg1ekw2VvuiZpMTRlqMhM6EqTn6RI+MzGFju5SOhdQ1SJ1Ty8= X-Received: by 2002:aca:b803:: with SMTP id i3mr4976678oif.92.1585957817931; Fri, 03 Apr 2020 16:50:17 -0700 (PDT) MIME-Version: 1.0 References: <20200226135229.24929-1-matthias.schiffer@ew.tq-group.com> <20200226151034.7i3h5blmrwre2yzg@pengutronix.de> <32ec35c2b3da119dd2c7bc09742796a0d8a9607e.camel@ew.tq-group.com> <20200330151231.GA1650@workstation.tuxnet> In-Reply-To: <20200330151231.GA1650@workstation.tuxnet> From: Sven Van Asbroeck Date: Fri, 3 Apr 2020 19:50:07 -0400 Message-ID: Subject: Re: (EXT) Re: [PATCH 1/4] pwm: pca9685: remove unused duty_cycle struct element To: Clemens Gruber Cc: Matthias Schiffer , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Thierry Reding , linux-pwm@vger.kernel.org, Linux Kernel Mailing List , Andy Shevchenko Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 30, 2020 at 11:12 AM Clemens Gruber wrote: > > On Wed, Feb 26, 2020 at 06:03:02PM +0100, Matthias Schiffer wrote: > > As it turns out, this driver is broken in yet another way I didn't find > > before: For changing the global prescaler the chip needs to be put into > > sleep mode, but the driver doesn't follow the restart sequence > > described in the datasheet when waking it back up. In consequence, > > changing the period of one PWM does not only modify the period of all > > PWMs (which is bad enough, but can't be avoided with this hardware), > > but it also leaves all PWMs disabled... > > I am unable to reproduce this: If I set a specific duty cycle on a > channel and then change the period, the channel stays active. > I can see the brightness of an LED decrease if I increase the period. What happens when pwm channels 0 and 1 are both enabled, and you change the pwm period of channel 0. Does channel 1 remain on?