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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 83F0CC43441 for ; Mon, 19 Nov 2018 19:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5441C20851 for ; Mon, 19 Nov 2018 19:05:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5441C20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=st.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730125AbeKTFaZ convert rfc822-to-8bit (ORCPT ); Tue, 20 Nov 2018 00:30:25 -0500 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:38315 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbeKTFaY (ORCPT ); Tue, 20 Nov 2018 00:30:24 -0500 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id wAJJ4cJu008801; Mon, 19 Nov 2018 20:05:01 +0100 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2nt9b24d1n-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 19 Nov 2018 20:05:01 +0100 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 304F13A; Mon, 19 Nov 2018 19:04:59 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id AEC3A53E5; Mon, 19 Nov 2018 19:04:59 +0000 (GMT) Received: from SFHDAG2NODE1.st.com (10.75.127.4) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 19 Nov 2018 20:04:59 +0100 Received: from SFHDAG2NODE1.st.com ([fe80::4413:c8c:992b:bb90]) by SFHDAG2NODE1.st.com ([fe80::4413:c8c:992b:bb90%20]) with mapi id 15.00.1347.000; Mon, 19 Nov 2018 20:04:59 +0100 From: Denis CIOCCA To: Jian-Hong Pan , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , "Dominique Martinet" CC: "linux-iio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux@endlessm.com" Subject: RE: [PATCH] iio: st_sensors: Fix the sleep time for sampling Thread-Topic: [PATCH] iio: st_sensors: Fix the sleep time for sampling Thread-Index: AQHUf87jF996TGSh6kGbSgzQPMw9KKVXc4KA Date: Mon, 19 Nov 2018 19:04:59 +0000 Message-ID: <04d0345d6c6c4ac0950ab0676ffd7689@SFHDAG2NODE1.st.com> References: <20181119061219.14238-1-jian-hong@endlessm.com> In-Reply-To: <20181119061219.14238-1-jian-hong@endlessm.com> Accept-Language: it-IT, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.50] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-19_06:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jian, Not clear to me why should be + instead of *. ODR is expressed in Hz, so (1/Hz) = period in seconds (1 sample sampling time) [s] 1000 * (1/Hz) = period in milliseconds (1 sample sampling time) [ms] n * 1000 * (1/Hz) = n times period in milliseconds (n times sample sampling time) [ms] In your case you assume bootime is in milliseconds. Maybe we can change the comment and use 'number of samples ...'. Br, Denis -----Original Message----- From: linux-iio-owner@vger.kernel.org On Behalf Of Jian-Hong Pan Sent: Sunday, November 18, 2018 10:12 PM To: Jonathan Cameron ; Hartmut Knaack ; Lars-Peter Clausen ; Peter Meerwald-Stadler ; Dominique Martinet Cc: linux-iio@vger.kernel.org; linux-kernel@vger.kernel.org; linux@endlessm.com; Jian-Hong Pan Subject: [PATCH] iio: st_sensors: Fix the sleep time for sampling According to the description of st_sensor_settings and st_sensor_data structures' comments: - bootime: samples to discard when sensor passing from power-down to power-up. - odr: Output data rate of the sensor [Hz]. The sleep time should be sdata->sensor_settings->bootime + 1000 / sdata->odr ms. Signed-off-by: Jian-Hong Pan --- drivers/iio/common/st_sensors/st_sensors_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c index 26fbd1bd9413..6b87ea657a92 100644 --- a/drivers/iio/common/st_sensors/st_sensors_core.c +++ b/drivers/iio/common/st_sensors/st_sensors_core.c @@ -594,7 +594,7 @@ int st_sensors_read_info_raw(struct iio_dev *indio_dev, if (err < 0) goto out; - msleep((sdata->sensor_settings->bootime * 1000) / sdata->odr); + msleep(sdata->sensor_settings->bootime + 1000 / sdata->odr); err = st_sensors_read_axis_data(indio_dev, ch, val); if (err < 0) goto out; -- 2.11.0