From patchwork Thu Sep 16 15:56:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 513800 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 A18A0C433FE for ; Thu, 16 Sep 2021 17:08:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DD4960EFF for ; Thu, 16 Sep 2021 17:08:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245325AbhIPRKD (ORCPT ); Thu, 16 Sep 2021 13:10:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:37132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237857AbhIPRHU (ORCPT ); Thu, 16 Sep 2021 13:07:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3408161B2B; Thu, 16 Sep 2021 16:36:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810166; bh=rBUMzl3onosp598T5s5G9TA9eIJrYtyHlU6jND7CCzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0ixcatMbZ0TucVyBFz2b9u3dVUXK9xe6jHV1JgfajL0HDcl8gA2j5/B1zMGV04an3 FOyddCs8FsABfbOeuVZtqEOphAYFekGlrrHqco2FzSc1k0a83ObzB/uGB7V4uhzthK l15LF3a7DhH7HEpW2dG+rzYmP1CLMRUI2bbaFGK8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Drew Fustini , =?utf-8?q?Nuno_S=C3=A1?= , Andy Shevchenko , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 5.14 041/432] iio: ltc2983: fix device probe Date: Thu, 16 Sep 2021 17:56:30 +0200 Message-Id: <20210916155812.209482033@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nuno Sá commit b76d26d69ecc97ebb24aaf40427a13c808a4f488 upstream. 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. Fix 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-and-tested-by: Drew Fustini Reviewed-by: Drew Fustini Signed-off-by: Nuno Sá Reviewed-by: Andy Shevchenko Cc: Link: https://lore.kernel.org/r/20210811133220.190264-2-nuno.sa@analog.com Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/temperature/ltc2983.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) --- 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) \ @@ -1362,17 +1364,16 @@ put_child: 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; int ret; - unsigned long time; - - /* make sure the device is up */ - time = wait_for_completion_timeout(&st->completion, - msecs_to_jiffies(250)); - if (!time) { + /* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */ + ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status, + LTC2983_STATUS_UP(status) == 1, 25000, + 25000 * 10); + if (ret) { dev_err(&st->spi->dev, "Device startup timed out\n"); - return -ETIMEDOUT; + return ret; } st->iio_chan = devm_kzalloc(&st->spi->dev, @@ -1492,10 +1493,11 @@ static int ltc2983_probe(struct spi_devi 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 +1505,6 @@ static int ltc2983_probe(struct spi_devi 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;