static ssize_t comp_write()

in most_cdev.c [182:227]

• 40 lines of code
• 11 McCabe index (conditional complexity)

static ssize_t comp_write(struct file *filp, const char __user *buf,
			  size_t count, loff_t *offset)
{
	int ret;
	size_t to_copy, left;
	struct mbo *mbo = NULL;
	struct comp_channel *c = filp->private_data;

	mutex_lock(&c->io_mutex);
	while (c->dev && !ch_get_mbo(c, &mbo)) {
		mutex_unlock(&c->io_mutex);

		if ((filp->f_flags & O_NONBLOCK))
			return -EAGAIN;
		if (wait_event_interruptible(c->wq, ch_has_mbo(c) || !c->dev))
			return -ERESTARTSYS;
		mutex_lock(&c->io_mutex);
	}

	if (unlikely(!c->dev)) {
		ret = -ENODEV;
		goto unlock;
	}

	to_copy = min(count, c->cfg->buffer_size - c->mbo_offs);
	left = copy_from_user(mbo->virt_address + c->mbo_offs, buf, to_copy);
	if (left == to_copy) {
		ret = -EFAULT;
		goto unlock;
	}

	c->mbo_offs += to_copy - left;
	if (c->mbo_offs >= c->cfg->buffer_size ||
	    c->cfg->data_type == MOST_CH_CONTROL ||
	    c->cfg->data_type == MOST_CH_ASYNC) {
		kfifo_skip(&c->fifo);
		mbo->buffer_length = c->mbo_offs;
		c->mbo_offs = 0;
		most_submit_mbo(mbo);
	}

	ret = to_copy - left;
unlock:
	mutex_unlock(&c->io_mutex);
	return ret;
}