From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:47244 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752396Ab3JLLFg (ORCPT ); Sat, 12 Oct 2013 07:05:36 -0400 Message-ID: <52593B2F.6090102@kernel.org> Date: Sat, 12 Oct 2013 13:06:07 +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> <52592E09.30507@kernel.org> <5259221C.4040309@metafoo.de> In-Reply-To: <5259221C.4040309@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 10/12/13 11:19, Lars-Peter Clausen wrote: > On 10/12/2013 01:10 PM, Jonathan Cameron wrote: >> 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?? > > This is to catch the case where we've set one (or both) of them to NULL > because it was already in the requested state. > Ah, as I said. Not enough coffee ;) >> >> 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; >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >