From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <5259221C.4040309@metafoo.de> Date: Sat, 12 Oct 2013 12:19:08 +0200 From: Lars-Peter Clausen MIME-Version: 1.0 To: Jonathan Cameron 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> In-Reply-To: <52592E09.30507@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 List-ID: 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. > > 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 >