From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:56565 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752211Ab3IUK5i (ORCPT ); Sat, 21 Sep 2013 06:57:38 -0400 Message-ID: <523D89C6.3060001@kernel.org> Date: Sat, 21 Sep 2013 12:57:58 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen CC: linux-iio@vger.kernel.org Subject: Re: [PATCH 10/10] iio:buffer: Ignore noop requests for iio_update_buffers() References: <1379534574-11213-1-git-send-email-lars@metafoo.de> <1379534574-11213-10-git-send-email-lars@metafoo.de> In-Reply-To: <1379534574-11213-10-git-send-email-lars@metafoo.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 09/18/13 21:02, Lars-Peter Clausen wrote: > Since the kernel now disables all buffers when a device is unregistered it might > happen that a in-kernel consumer tries to disable that buffer again. So ignore > requests where the buffer already is in the desired state. > > Signed-off-by: Lars-Peter Clausen > --- > drivers/iio/industrialio-buffer.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index 8ceaaaf..2b36cea 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -673,9 +673,21 @@ int iio_update_buffers(struct iio_dev *indio_dev, > { > int ret; > > + if (insert_buffer == remove_buffer) > + return 0; > + Can this first case occur without a bug in the calling function? The rest are fine. > mutex_lock(&indio_dev->info_exist_lock); > mutex_lock(&indio_dev->mlock); > > + if (insert_buffer && iio_buffer_is_active(insert_buffer)) > + insert_buffer = NULL; > + > + if (remove_buffer && !iio_buffer_is_active(remove_buffer)) > + remove_buffer = NULL; > + > + if (!insert_buffer && !remove_buffer) > + return 0; > + > if (indio_dev->info == NULL) > return -ENODEV; > >