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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham 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 F1EC3C43381 for ; Mon, 25 Mar 2019 08:50:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA9F220863 for ; Mon, 25 Mar 2019 08:50:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730152AbfCYIup (ORCPT ); Mon, 25 Mar 2019 04:50:45 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:49487 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730076AbfCYIuo (ORCPT ); Mon, 25 Mar 2019 04:50:44 -0400 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1h8LJW-0001dy-02; Mon, 25 Mar 2019 09:50:38 +0100 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1h8LJV-0005sp-LY; Mon, 25 Mar 2019 09:50:37 +0100 Date: Mon, 25 Mar 2019 09:50:37 +0100 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Martin Blumenstingl Cc: thierry.reding@gmail.com, narmstrong@baylibre.com, jbrunet@baylibre.com, linux-pwm@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/1] pwm: meson: fix scheduling while atomic issue Message-ID: <20190325085037.f4weycbhaa7yyurt@pengutronix.de> References: <20190324220217.15813-1-martin.blumenstingl@googlemail.com> <20190325084153.l44pzfewcqlkoaoe@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190325084153.l44pzfewcqlkoaoe@pengutronix.de> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Mon, Mar 25, 2019 at 09:41:53AM +0100, Uwe Kleine-König wrote: > If you want to implement further cleanups, my questions and propositions > are: > > - Is there a publicly available manual for this hardware? If yes, you > can add a link to it in the header of the driver. > > - Why do you handle reparenting of the PWM's clk in .request? Wouldn't > this be more suitable in .apply? > > - Does stopping the PWM (i.e. clearing MISC_{A,B}_EN in the MISC_AB > register) freeze the output, or is the currently running period > completed first? (The latter is the right behaviour.) > > - Please point out in the header that for changing period/duty > cycle/polarity the hardware must be stopped. (I suggest to apply the > style used in https://www.spinics.net/lists/linux-pwm/msg09262.html > for some consistency.) Another thing I just noted: The .get_state callback only sets .enabled but nothing of the remaining information is provided. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |