From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754115AbcEXTRB (ORCPT ); Tue, 24 May 2016 15:17:01 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:32804 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752025AbcEXTQ7 (ORCPT ); Tue, 24 May 2016 15:16:59 -0400 Date: Tue, 24 May 2016 12:16:57 -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 2/7] iio: adc: ad7791: claim direct mode when writing frequency Message-ID: 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/ad7791.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/iio/adc/ad7791.c b/drivers/iio/adc/ad7791.c index cf172d58..f7edacc 100644 --- a/drivers/iio/adc/ad7791.c +++ b/drivers/iio/adc/ad7791.c @@ -272,24 +272,17 @@ static ssize_t ad7791_write_frequency(struct device *dev, struct ad7791_state *st = iio_priv(indio_dev); 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 = -EINVAL; - for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) { - mutex_lock(&indio_dev->mlock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; st->filter &= ~AD7791_FILTER_RATE_MASK; st->filter |= i; ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, sizeof(st->filter), st->filter); - mutex_unlock(&indio_dev->mlock); + iio_device_release_direct_mode(indio_dev); ret = 0; break; } -- 2.1.4