From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754174AbcEXTRc (ORCPT ); Tue, 24 May 2016 15:17:32 -0400 Received: from mail-pa0-f68.google.com ([209.85.220.68]:33182 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751625AbcEXTRa (ORCPT ); Tue, 24 May 2016 15:17:30 -0400 Date: Tue, 24 May 2016 12:17:27 -0700 From: Alison Schofield To: jic23@kernel.org Cc: lars@metafoo.de, Michael.Hennerich@analog.com, knaack.h@gmx.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/7] iio: adc: ad7793: claim direct mode when writing frequency Message-ID: <96cee774e7a4269a73b0fcd476d8af575c10ac00.1464115008.git.amsfield22@gmail.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Driver was checking for direct mode and trying to lock it, but left a gap where mode could change before the desired operation. Use iio_device_claim_direct_mode() to guarantee device stays in direct mode. Signed-off-by: Alison Schofield Cc: Daniel Baluta --- drivers/iio/adc/ad7793.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c index 7b07bb6..3f41cd8 100644 --- a/drivers/iio/adc/ad7793.c +++ b/drivers/iio/adc/ad7793.c @@ -369,13 +369,6 @@ static ssize_t ad7793_write_frequency(struct device *dev, long lval; int i, ret; - mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&indio_dev->mlock); - return -EBUSY; - } - mutex_unlock(&indio_dev->mlock); - ret = kstrtol(buf, 10, &lval); if (ret) return ret; @@ -387,12 +380,14 @@ static ssize_t ad7793_write_frequency(struct device *dev, for (i = 0; i < 16; i++) if (lval == st->chip_info->sample_freq_avail[i]) { - mutex_lock(&indio_dev->mlock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; st->mode &= ~AD7793_MODE_RATE(-1); st->mode |= AD7793_MODE_RATE(i); ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode), st->mode); - mutex_unlock(&indio_dev->mlock); + iio_device_release_direct_mode(indio_dev); ret = 0; } -- 2.1.4