From patchwork Tue Aug 10 14:56:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nuno Sa X-Patchwork-Id: 12429063 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9AE83C4338F for ; Tue, 10 Aug 2021 14:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6355E60F25 for ; Tue, 10 Aug 2021 14:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237711AbhHJOzA (ORCPT ); Tue, 10 Aug 2021 10:55:00 -0400 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:21044 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232874AbhHJOzA (ORCPT ); Tue, 10 Aug 2021 10:55:00 -0400 Received: from pps.filterd (m0167088.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 17AEfWkD012611; Tue, 10 Aug 2021 10:54:03 -0400 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com with ESMTP id 3ab966aymq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Aug 2021 10:54:03 -0400 Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 17AEs2oS027591 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 10 Aug 2021 10:54:02 -0400 Received: from ASHBMBX9.ad.analog.com (10.64.17.10) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.858.5; Tue, 10 Aug 2021 10:54:01 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server id 15.2.858.5 via Frontend Transport; Tue, 10 Aug 2021 10:54:01 -0400 Received: from nsa.ad.analog.com ([10.44.3.58]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 17AErxKZ005253; Tue, 10 Aug 2021 10:54:00 -0400 From: =?utf-8?q?Nuno_S=C3=A1?= To: CC: =Jonathan Cameron , Lars-Peter Clausen , Drew Fustini Subject: [PATCH 1/1] iio: ltc2983: fix device probe Date: Tue, 10 Aug 2021 16:56:53 +0200 Message-ID: <20210810145653.295397-2-nuno.sa@analog.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810145653.295397-1-nuno.sa@analog.com> References: <20210810145653.295397-1-nuno.sa@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: DT6GkvaFyEm9qNYgYsIjwKH5iXLF2lUb X-Proofpoint-ORIG-GUID: DT6GkvaFyEm9qNYgYsIjwKH5iXLF2lUb X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-08-10_06:2021-08-10,2021-08-10 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 adultscore=0 lowpriorityscore=0 clxscore=1015 malwarescore=0 spamscore=0 suspectscore=0 mlxscore=0 impostorscore=0 phishscore=0 priorityscore=1501 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108100092 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org There is no reason to assume that the irq rising edge (indicating that the device start up phase is done) will happen after we request the irq. If the device is already up by the time we request it, the call to 'wait_for_completion_timeout()' will timeout and we will fail the device probe even though there's nothing wrong. This patch fixes it by just polling the status register until we get the indication that the device is up and running. As a side effect of this fix, requesting the irq is also moved to after the setup function. Fixes: f110f3188e563 ("iio: temperature: Add support for LTC2983") Reported-by: Drew Fustini Signed-off-by: Nuno Sá Reviewed-by: Drew Fustini Tested-by: Drew Fustini --- drivers/iio/temperature/ltc2983.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c index 3b5ba26d7d86..c6c4877bdcff 100644 --- a/drivers/iio/temperature/ltc2983.c +++ b/drivers/iio/temperature/ltc2983.c @@ -89,6 +89,8 @@ #define LTC2983_STATUS_START_MASK BIT(7) #define LTC2983_STATUS_START(x) FIELD_PREP(LTC2983_STATUS_START_MASK, x) +#define LTC2983_STATUS_UP_MASK GENMASK(7, 6) +#define LTC2983_STATUS_UP(reg) FIELD_GET(LTC2983_STATUS_UP_MASK, reg) #define LTC2983_STATUS_CHAN_SEL_MASK GENMASK(4, 0) #define LTC2983_STATUS_CHAN_SEL(x) \ @@ -1362,13 +1364,21 @@ static int ltc2983_parse_dt(struct ltc2983_data *st) static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) { - u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0; + u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status = 0; int ret; - unsigned long time; + unsigned long time = 10; /* make sure the device is up */ - time = wait_for_completion_timeout(&st->completion, - msecs_to_jiffies(250)); + do { + ret = regmap_read(st->regmap, LTC2983_STATUS_REG, &status); + if (ret) + return ret; + /* start bit (7) is 0 and done bit (6) is 1 */ + if (LTC2983_STATUS_UP(status) == 1) + break; + + msleep(25); + } while (--time); if (!time) { dev_err(&st->spi->dev, "Device startup timed out\n"); @@ -1492,10 +1502,11 @@ static int ltc2983_probe(struct spi_device *spi) ret = ltc2983_parse_dt(st); if (ret) return ret; - /* - * let's request the irq now so it is used to sync the device - * startup in ltc2983_setup() - */ + + ret = ltc2983_setup(st, true); + if (ret) + return ret; + ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler, IRQF_TRIGGER_RISING, name, st); if (ret) { @@ -1503,10 +1514,6 @@ static int ltc2983_probe(struct spi_device *spi) return ret; } - ret = ltc2983_setup(st, true); - if (ret) - return ret; - indio_dev->name = name; indio_dev->num_channels = st->iio_channels; indio_dev->channels = st->iio_chan;