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 <lars@xxxxxxxxxx>
---
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 e73033f..96e97ad 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;
--
1.8.0
--
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