1 files changed, 52 insertions, 6 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 0f6f63b20..139ae9162 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -193,7 +193,8 @@ void iio_buffer_init(struct iio_buffer *buffer)
 	INIT_LIST_HEAD(&buffer->buffer_list);
 	init_waitqueue_head(&buffer->pollq);
 	kref_init(&buffer->ref);
-	buffer->watermark = 1;
+	if (!buffer->watermark)
+		buffer->watermark = 1;
 }
 EXPORT_SYMBOL(iio_buffer_init);
 
@@ -567,6 +568,22 @@ static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
 		iio_buffer_deactivate(buffer);
 }
 
+static int iio_buffer_enable(struct iio_buffer *buffer,
+	struct iio_dev *indio_dev)
+{
+	if (!buffer->access->enable)
+		return 0;
+	return buffer->access->enable(buffer, indio_dev);
+}
+
+static int iio_buffer_disable(struct iio_buffer *buffer,
+	struct iio_dev *indio_dev)
+{
+	if (!buffer->access->disable)
+		return 0;
+	return buffer->access->disable(buffer, indio_dev);
+}
+
 static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
 	struct iio_buffer *buffer)
 {
@@ -610,6 +627,7 @@ static void iio_free_scan_mask(struct iio_dev *indio_dev,
 
 struct iio_device_config {
 	unsigned int mode;
+	unsigned int watermark;
 	const unsigned long *scan_mask;
 	unsigned int scan_bytes;
 	bool scan_timestamp;
@@ -642,10 +660,14 @@ static int iio_verify_update(struct iio_dev *indio_dev,
 		if (buffer == remove_buffer)
 			continue;
 		modes &= buffer->access->modes;
+		config->watermark = min(config->watermark, buffer->watermark);
 	}
 
-	if (insert_buffer)
+	if (insert_buffer) {
 		modes &= insert_buffer->access->modes;
+		config->watermark = min(config->watermark,
+			insert_buffer->watermark);
+	}
 
 	/* Definitely possible for devices to support both of these. */
 	if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
@@ -713,6 +735,7 @@ static int iio_verify_update(struct iio_dev *indio_dev,
 static int iio_enable_buffers(struct iio_dev *indio_dev,
 	struct iio_device_config *config)
 {
+	struct iio_buffer *buffer;
 	int ret;
 
 	indio_dev->active_scan_mask = config->scan_mask;
@@ -743,6 +766,16 @@ static int iio_enable_buffers(struct iio_dev *indio_dev,
 		}
 	}
 
+	if (indio_dev->info->hwfifo_set_watermark)
+		indio_dev->info->hwfifo_set_watermark(indio_dev,
+			config->watermark);
+
+	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
+		ret = iio_buffer_enable(buffer, indio_dev);
+		if (ret)
+			goto err_disable_buffers;
+	}
+
 	indio_dev->currentmode = config->mode;
 
 	if (indio_dev->setup_ops->postenable) {
@@ -750,12 +783,16 @@ static int iio_enable_buffers(struct iio_dev *indio_dev,
 		if (ret) {
 			dev_dbg(&indio_dev->dev,
 			       "Buffer not started: postenable failed (%d)\n", ret);
-			goto err_run_postdisable;
+			goto err_disable_buffers;
 		}
 	}
 
 	return 0;
 
+err_disable_buffers:
+	list_for_each_entry_continue_reverse(buffer, &indio_dev->buffer_list,
+					     buffer_list)
+		iio_buffer_disable(buffer, indio_dev);
 err_run_postdisable:
 	indio_dev->currentmode = INDIO_DIRECT_MODE;
 	if (indio_dev->setup_ops->postdisable)
@@ -768,6 +805,7 @@ err_undo_config:
 
 static int iio_disable_buffers(struct iio_dev *indio_dev)
 {
+	struct iio_buffer *buffer;
 	int ret = 0;
 	int ret2;
 
@@ -788,6 +826,12 @@ static int iio_disable_buffers(struct iio_dev *indio_dev)
 			ret = ret2;
 	}
 
+	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
+		ret2 = iio_buffer_disable(buffer, indio_dev);
+		if (ret2 && !ret)
+			ret = ret2;
+	}
+
 	indio_dev->currentmode = INDIO_DIRECT_MODE;
 
 	if (indio_dev->setup_ops->postdisable) {
@@ -974,9 +1018,6 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
 	}
 
 	buffer->watermark = val;
-
-	if (indio_dev->info->hwfifo_set_watermark)
-		indio_dev->info->hwfifo_set_watermark(indio_dev, val);
 out:
 	mutex_unlock(&indio_dev->mlock);
 
@@ -991,6 +1032,8 @@ static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
 		   iio_buffer_show_enable, iio_buffer_store_enable);
 static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
 		   iio_buffer_show_watermark, iio_buffer_store_watermark);
+static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
+	S_IRUGO, iio_buffer_show_watermark, NULL);
 
 static struct attribute *iio_buffer_attrs[] = {
 	&dev_attr_length.attr,
@@ -1033,6 +1076,9 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
 	if (!buffer->access->set_length)
 		attr[0] = &dev_attr_length_ro.attr;
 
+	if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
+		attr[2] = &dev_attr_watermark_ro.attr;
+
 	if (buffer->attrs)
 		memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
 		       sizeof(struct attribute *) * attrcount);