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=-0.8 required=3.0 tests=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 189FCC433E1 for ; Thu, 9 Jul 2020 14:50:18 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E561320767 for ; Thu, 9 Jul 2020 14:50:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E561320767 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 85A776E8E8; Thu, 9 Jul 2020 14:50:17 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8FC996E8E8; Thu, 9 Jul 2020 14:50:16 +0000 (UTC) IronPort-SDR: k3lQLpFhIIusNct/Tv50e6z8rntkwGwYvuocRIfQcVp7JOcg2oxx5xv/s4TvXvdADlV31U+4h0 2O9fTa3ZJRKw== X-IronPort-AV: E=McAfee;i="6000,8403,9677"; a="232881522" X-IronPort-AV: E=Sophos;i="5.75,331,1589266800"; d="scan'208";a="232881522" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jul 2020 07:50:16 -0700 IronPort-SDR: D/XUYMSp7pV3RqXOFUNrDLm8myVFN+vUXCjDbk4u4enIZwh5VeaP3rkTuAjMvg45USqZ04zgtD IrKqRKUSO7lA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,331,1589266800"; d="scan'208";a="389163251" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga001.fm.intel.com with ESMTP; 09 Jul 2020 07:50:13 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jtXsL-000sMF-Dd; Thu, 09 Jul 2020 17:50:13 +0300 Date: Thu, 9 Jul 2020 17:50:13 +0300 From: Andy Shevchenko To: Hans de Goede Message-ID: <20200709145013.GA3703480@smile.fi.intel.com> References: <20200708211432.28612-1-hdegoede@redhat.com> <20200708211432.28612-7-hdegoede@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200708211432.28612-7-hdegoede@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Subject: Re: [Intel-gfx] [PATCH v4 06/16] pwm: lpss: Correct get_state result for base_unit == 0 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, intel-gfx , "Rafael J . Wysocki" , linux-acpi@vger.kernel.org, dri-devel@lists.freedesktop.org, Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Mika Westerberg , Len Brown Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Jul 08, 2020 at 11:14:22PM +0200, Hans de Goede wrote: > The datasheet specifies that programming the base_unit part of the > ctrl register to 0 results in a contineous low signal. > > Adjust the get_state method to reflect this by setting pwm_state.period > to 1 and duty_cycle to 0. ... > + if (freq == 0) { > + /* In this case the PWM outputs a continous low signal */ > + state->period = 1; I guess this should be something like half of the range (so base unit calc will give 128). Because with period = 1 (too small) it will give too small base unit (if apply) and as a result we get high frequency pulses. > + state->duty_cycle = 0; > + } else { > state->period = NSEC_PER_SEC / (unsigned long)freq; > + on_time_div *= state->period; > + do_div(on_time_div, 255); > + state->duty_cycle = on_time_div; > + } -- With Best Regards, Andy Shevchenko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx