From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49856 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754151AbdKMM75 (ORCPT ); Mon, 13 Nov 2017 07:59:57 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alison Schofield , Jonathan Cameron , Sasha Levin Subject: [PATCH 4.9 22/87] iio: pressure: ms5611: claim direct mode during oversampling changes Date: Mon, 13 Nov 2017 13:55:39 +0100 Message-Id: <20171113125617.423505106@linuxfoundation.org> In-Reply-To: <20171113125615.304035578@linuxfoundation.org> References: <20171113125615.304035578@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alison Schofield [ Upstream commit 3bc1abcddb24f55b9c251e03caa4f9bd22ff748b ] Driver was checking for direct mode before changing oversampling ratios, but was not locking it. Use the claim/release helper functions to guarantee the device stays in direct mode while the oversampling ratios are being updated. Continue to use the drivers private state lock to protect against conflicting direct mode access of the state data. Signed-off-by: Alison Schofield Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iio/pressure/ms5611_core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -308,6 +308,7 @@ static int ms5611_write_raw(struct iio_d { struct ms5611_state *st = iio_priv(indio_dev); const struct ms5611_osr *osr = NULL; + int ret; if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) return -EINVAL; @@ -321,12 +322,11 @@ static int ms5611_write_raw(struct iio_d if (!osr) return -EINVAL; - mutex_lock(&st->lock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; - if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&st->lock); - return -EBUSY; - } + mutex_lock(&st->lock); if (chan->type == IIO_TEMP) st->temp_osr = osr; @@ -334,6 +334,8 @@ static int ms5611_write_raw(struct iio_d st->pressure_osr = osr; mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + return 0; }