From fcc1b2f57d89142acf6173a8e6ffb19f5f5ec876 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 13 May 2015 16:04:46 +0200 Subject: [PATCH] iio: __iio_update_buffers: Perform request_update() only for new buffers We only have to call the request_update() callback for a newly inserted buffer. The configuration of the already previously active buffers will not have changed. This also allows us to move the request_update() call to the beginning of __iio_update_buffers(), before any currently active buffers are stopped. This makes the error handling a lot easier since no changes were made to the buffer list and no rollback needs to be performed. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-buffer.c | 36 +++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 11 deletions(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 2afe3dbd8d3d..21ed3168b70b 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -575,6 +575,25 @@ static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev, buffer->access->set_bytes_per_datum(buffer, bytes); } +static int iio_buffer_request_update(struct iio_dev *indio_dev, + struct iio_buffer *buffer) +{ + int ret; + + iio_buffer_update_bytes_per_datum(indio_dev, buffer); + if (buffer->access->request_update) { + ret = buffer->access->request_update(buffer); + if (ret) { + dev_dbg(&indio_dev->dev, + "Buffer not started: buffer parameter update failed (%d)\n", + ret); + return ret; + } + } + + return 0; +} + static void iio_free_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) { @@ -593,6 +612,12 @@ static int __iio_update_buffers(struct iio_dev *indio_dev, unsigned long *compound_mask; const unsigned long *old_mask; + if (insert_buffer) { + ret = iio_buffer_request_update(indio_dev, insert_buffer); + if (ret) + return ret; + } + /* Wind down existing buffers - iff there are any */ if (!list_empty(&indio_dev->buffer_list)) { if (indio_dev->setup_ops->predisable) { @@ -678,17 +703,6 @@ static int __iio_update_buffers(struct iio_dev *indio_dev, iio_compute_scan_bytes(indio_dev, indio_dev->active_scan_mask, indio_dev->scan_timestamp); - list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { - iio_buffer_update_bytes_per_datum(indio_dev, buffer); - if (buffer->access->request_update) { - ret = buffer->access->request_update(buffer); - if (ret) { - dev_dbg(&indio_dev->dev, - "Buffer not started: buffer parameter update failed (%d)\n", ret); - goto error_run_postdisable; - } - } - } if (indio_dev->info->update_scan_mode) { ret = indio_dev->info ->update_scan_mode(indio_dev, -- 2.39.5