From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:46484 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753570Ab3JLKJb (ORCPT ); Sat, 12 Oct 2013 06:09:31 -0400 Message-ID: <52592E09.30507@kernel.org> Date: Sat, 12 Oct 2013 12:10:01 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen CC: linux-iio@vger.kernel.org Subject: Re: [PATCH v2 5/5] iio:buffer: Ignore noop requests for iio_update_buffers() References: <1380884822-17035-1-git-send-email-lars@metafoo.de> <1380884822-17035-5-git-send-email-lars@metafoo.de> In-Reply-To: <1380884822-17035-5-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 10/04/13 12:07, 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 > --- > No changes since v1 > --- > drivers/iio/industrialio-buffer.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index d6a5455..fd3f3af 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -681,9 +681,23 @@ int iio_update_buffers(struct iio_dev *indio_dev, > { > int ret; > > + if (insert_buffer == remove_buffer) > + return 0; > + > 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; > + So this condition will occur iff insert_buffer = 0 and remove buffer = 0? If so, then insert_buffer == remove_buffer and you'll have already returned 0 above?? Entirely possible I'm needing more coffee this morning... > + if (!insert_buffer && !remove_buffer) { > + ret = 0; > + goto out_unlock; > + } > + > if (indio_dev->info == NULL) { > ret = -ENODEV; > goto out_unlock; >