From patchwork Wed Sep 27 06:31:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aastha Gupta X-Patchwork-Id: 9973195 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id ABF6660375 for ; Wed, 27 Sep 2017 06:32:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E125290BE for ; Wed, 27 Sep 2017 06:32:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9CBAC290C5; Wed, 27 Sep 2017 06:32:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B484F290C4 for ; Wed, 27 Sep 2017 06:32:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751134AbdI0Gc3 (ORCPT ); Wed, 27 Sep 2017 02:32:29 -0400 Received: from mail-pg0-f68.google.com ([74.125.83.68]:37013 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbdI0Gc2 (ORCPT ); Wed, 27 Sep 2017 02:32:28 -0400 Received: by mail-pg0-f68.google.com with SMTP id v5so8153189pgn.4 for ; Tue, 26 Sep 2017 23:32:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=/OekZeAHhXmlYVkl5wskY6tdPEW+gmonECBDGfmQCxo=; b=UkdOdHDdZViVHRPbX1Sxy1SStj/cwNGRa3KIsQtNVoRIPrptaLfgbg+RRbs0PjHkkF TESgN3yUQKHRqP24Rr/fdGpwOaKHRhX2R+hCxC67JWUB2fSUnThjLXtO5ty3fTpUY3X3 sifZ+n97ONvVHBqKCEB7MYQT87H1GnN5eZiPyeJ9VU5iv1nJdUFc48zUZZQBwYKJvIWR o0LI7zF7LAwWETmnnJoEPd8802ZjPkP5eIJYdSWDDcrR2T2f/wEyKmkLab110SNbXrVd fccY3rLvcgKp9YSKOVqUyxN6ZhBG+Od/0JTd2i71zPcvEhvZHSuE+BJwL2G/DE0gVyQI VfNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=/OekZeAHhXmlYVkl5wskY6tdPEW+gmonECBDGfmQCxo=; b=ehAd0Lo0IE2whxL3zCpcnD16cgIgHaiSmzNcSgrXniOrep3uhi0AtMryjVEkvdXoZE yHKKev0l//xH8md9C7PKZhiE+p00G0/HNQM9DqkM8CsiAUAj3lyv6IuOQQr6i8EhKymi xsDXmqO9YtCO1AItuC3oCg1KC2uZS1wAz7d9Bmr/4966NG0JBjTP8iXGql+Q1dlDZbN3 5942RoBEBlG+wwlcRv85Psc1Xea3gFnOxFkCLqQzeGMzqaiRjBTvTE8c43UKpQ0va8Nz kVxboJMnrKO2vTDYWS2acelS2nv+bhniroJoNT7MyZt5leePj5/HVoR7o90t/eJJIYy9 BLbQ== X-Gm-Message-State: AHPjjUj5436S+KvEjQRuStwVCUkgUIDlcHqwy4Zf0E9ZkyzrmJmcldhH 0IhYHpObzOaXgMQbIqPwReQ= X-Google-Smtp-Source: AOwi7QAoO1hAWjYDMVUglCgK4XQQqUNUMOOJGGVYLb1G6YBy3/QyMag3ffxDwvCPGdRh7MrkxyEG7g== X-Received: by 10.98.10.146 with SMTP id 18mr368870pfk.346.1506493947786; Tue, 26 Sep 2017 23:32:27 -0700 (PDT) Received: from aastha-HP-Pavilion-15-Notebook-PC ([47.31.2.166]) by smtp.gmail.com with ESMTPSA id l12sm23133301pgp.74.2017.09.26.23.32.25 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 26 Sep 2017 23:32:27 -0700 (PDT) From: Aastha Gupta To: outreachy-kernel@googlegroups.com, hennerich@blackfin.uclinux.org, jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org Cc: Aastha Gupta Subject: [PATCH v4] staging: iio: adc: ad7192: use driver private lock to protect hardware state changes Date: Wed, 27 Sep 2017 12:01:59 +0530 Message-Id: <1506493919-3189-1-git-send-email-aastha.gupta4104@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The IIO subsystem is redefining iio_dev->mlock to be used by the IIO core only for protecting device operating mode changes. ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes. In this driver, mlock was being used to protect hardware state changes. Replace it with a driver private lock. Also, as there are state changes in the ad7192_ write_raw function, a lock is added to prevent the concurrent state changes. Signed-off-by: Aastha Gupta --- changes in v4: - added comment for mutex - improved commit message drivers/staging/iio/adc/ad7192.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c index d11c6de..c1343ec 100644 --- a/drivers/staging/iio/adc/ad7192.c +++ b/drivers/staging/iio/adc/ad7192.c @@ -162,6 +162,7 @@ struct ad7192_state { u32 scale_avail[8][2]; u8 gpocon; u8 devid; + struct mutex lock; /* protect sensor state */ struct ad_sigma_delta sd; }; @@ -463,10 +464,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_VOLTAGE: - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); *val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0]; *val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1]; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return IIO_VAL_INT_PLUS_NANO; case IIO_TEMP: *val = 0; @@ -510,6 +511,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_SCALE: ret = -EINVAL; + mutex_lock(&st->lock); for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) if (val2 == st->scale_avail[i][1]) { ret = 0; @@ -523,6 +525,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev, ad7192_calibrate_all(st); break; } + mutex_unlock(&st->lock); break; case IIO_CHAN_INFO_SAMP_FREQ: if (!val) { @@ -634,6 +637,8 @@ static int ad7192_probe(struct spi_device *spi) st = iio_priv(indio_dev); + mutex_init(&st->lock); + st->avdd = devm_regulator_get(&spi->dev, "avdd"); if (IS_ERR(st->avdd)) return PTR_ERR(st->avdd);