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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 7A9FDC43603 for ; Tue, 10 Dec 2019 21:43:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4ABA520637 for ; Tue, 10 Dec 2019 21:43:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576014214; bh=nxiHqEEeAIgzmTb4XBX0ISbTYklaOzPKlV3P7FFHadc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bzN2f2QScznpF/E0m9Xhdz3ktBbpxtRv500vZ8PohPYYqIku5dQgFiYwIdzT13x/i ufGMtFr2LUEV3ukzusIbj95MHyw972c1fQ5pVM4j5XcfNwacazpLO8qbQi23726Wu8 Eo110LmcL/8MqOemnJrXR2CosiaUqxj86YbR0EJk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729314AbfLJVnd (ORCPT ); Tue, 10 Dec 2019 16:43:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:38102 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729771AbfLJVdg (ORCPT ); Tue, 10 Dec 2019 16:33:36 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9A4B920836; Tue, 10 Dec 2019 21:33:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576013616; bh=nxiHqEEeAIgzmTb4XBX0ISbTYklaOzPKlV3P7FFHadc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nXKnuN9Q9J0urT/DVC6ABW7dwaj2jgDDjfeV5YkjP+qdTIueAgHzX/OaieeqpO5+z ycPhjXHfi/hWRwM+VeXI94ZrBFwY+rB6Rd3Oo9pN9MbNIkadpJ2/VF0EgSzbIzcKq+ JGwnlcsYcp50f4DIPLBkJRCl5NUGPJC7gwqJo9KA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexandru Ardelean , Jonathan Cameron , Sasha Levin , linux-iio@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 061/177] iio: dac: ad7303: replace mlock with own lock Date: Tue, 10 Dec 2019 16:30:25 -0500 Message-Id: <20191210213221.11921-61-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210213221.11921-1-sashal@kernel.org> References: <20191210213221.11921-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexandru Ardelean [ Upstream commit c991bf9b650f39481cf3c1137092d4754a2c75de ] This change replaces indio_dev's mlock with the driver's own lock. The lock is mostly needed to protect state when changing the `dac_cache` info. The lock has been extended to `ad7303_read_raw()`, to make sure that the cache is updated if an SPI-write is already in progress. Signed-off-by: Alexandru Ardelean Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/dac/ad7303.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/iio/dac/ad7303.c b/drivers/iio/dac/ad7303.c index 8f3bd19b6dc35..dc1aea5b579e4 100644 --- a/drivers/iio/dac/ad7303.c +++ b/drivers/iio/dac/ad7303.c @@ -42,6 +42,7 @@ struct ad7303_state { struct regulator *vdd_reg; struct regulator *vref_reg; + struct mutex lock; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -80,7 +81,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, if (ret) return ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); if (pwr_down) st->config |= AD7303_CFG_POWER_DOWN(chan->channel); @@ -91,7 +92,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, * mode, so just write one of the DAC channels again */ ad7303_write(st, chan->channel, st->dac_cache[chan->channel]); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return len; } @@ -117,7 +118,9 @@ static int ad7303_read_raw(struct iio_dev *indio_dev, switch (info) { case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); *val = st->dac_cache[chan->channel]; + mutex_unlock(&st->lock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: vref_uv = ad7303_get_vref(st, chan); @@ -145,11 +148,11 @@ static int ad7303_write_raw(struct iio_dev *indio_dev, if (val >= (1 << chan->scan_type.realbits) || val < 0) return -EINVAL; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); ret = ad7303_write(st, chan->address, val); if (ret == 0) st->dac_cache[chan->channel] = val; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); break; default: ret = -EINVAL; @@ -212,6 +215,8 @@ static int ad7303_probe(struct spi_device *spi) st->spi = spi; + mutex_init(&st->lock); + st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd"); if (IS_ERR(st->vdd_reg)) return PTR_ERR(st->vdd_reg); -- 2.20.1