From 705ee2c98a37130fd0aa914dc55b74a9174a6ff0 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Sun, 15 Sep 2013 16:31:00 +0100 Subject: [PATCH] iio:buffer: Simplify iio_buffer_is_active() We can skip having to loop through all the device's buffers to see if a certain buffer is active, if we let the buffer's list head point to itself when the buffer is inactive. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-buffer.c | 31 +++++++++++-------------------- 1 file changed, 11 insertions(+), 20 deletions(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index e73033f3839a..96e97ad2538c 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -31,16 +31,9 @@ static const char * const iio_endian_prefix[] = { [IIO_LE] = "le", }; -static bool iio_buffer_is_active(struct iio_dev *indio_dev, - struct iio_buffer *buf) +static bool iio_buffer_is_active(struct iio_buffer *buf) { - struct list_head *p; - - list_for_each(p, &indio_dev->buffer_list) - if (p == &buf->buffer_list) - return true; - - return false; + return !list_empty(&buf->buffer_list); } /** @@ -79,6 +72,7 @@ unsigned int iio_buffer_poll(struct file *filp, void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); + INIT_LIST_HEAD(&buffer->buffer_list); init_waitqueue_head(&buffer->pollq); } EXPORT_SYMBOL(iio_buffer_init); @@ -146,7 +140,7 @@ static ssize_t iio_scan_el_store(struct device *dev, if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } @@ -192,7 +186,7 @@ static ssize_t iio_scan_el_ts_store(struct device *dev, return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } @@ -396,7 +390,7 @@ ssize_t iio_buffer_write_length(struct device *dev, return len; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; } else { if (buffer->access->set_length) @@ -414,9 +408,7 @@ ssize_t iio_buffer_show_enable(struct device *dev, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); - return sprintf(buf, "%d\n", - iio_buffer_is_active(indio_dev, - indio_dev->buffer)); + return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer)); } EXPORT_SYMBOL(iio_buffer_show_enable); @@ -490,7 +482,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, indio_dev->active_scan_mask = NULL; if (remove_buffer) - list_del(&remove_buffer->buffer_list); + list_del_init(&remove_buffer->buffer_list); if (insert_buffer) list_add(&insert_buffer->buffer_list, &indio_dev->buffer_list); @@ -527,7 +519,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, * Roll back. * Note can only occur when adding a buffer. */ - list_del(&insert_buffer->buffer_list); + list_del_init(&insert_buffer->buffer_list); indio_dev->active_scan_mask = old_mask; success = -EINVAL; } @@ -611,7 +603,7 @@ error_run_postdisable: error_remove_inserted: if (insert_buffer) - list_del(&insert_buffer->buffer_list); + list_del_init(&insert_buffer->buffer_list); indio_dev->active_scan_mask = old_mask; kfree(compound_mask); error_ret: @@ -628,7 +620,6 @@ ssize_t iio_buffer_store_enable(struct device *dev, int ret; bool requested_state; struct iio_dev *indio_dev = dev_to_iio_dev(dev); - struct iio_buffer *pbuf = indio_dev->buffer; bool inlist; ret = strtobool(buf, &requested_state); @@ -638,7 +629,7 @@ ssize_t iio_buffer_store_enable(struct device *dev, mutex_lock(&indio_dev->mlock); /* Find out if it is in the list */ - inlist = iio_buffer_is_active(indio_dev, pbuf); + inlist = iio_buffer_is_active(indio_dev->buffer); /* Already in desired state */ if (inlist == requested_state) goto done; -- 2.30.2