Locking in the clk API, part 2: clk_prepare/clk_unprepare

On 02/01/2011 07:24 AM, Russell King - ARM Linux wrote:

I'd also be tempted at this stage to build-in a no-op dummy clock,
that being the NULL clk:

int clk_prepare(struct clk *clk)
{
	int ret = 0;

	if (clk) {
		mutex_lock(&clk->mutex);
		if (clk->prepared == 0)
			ret = clk->ops->prepare(clk);
		if (ret == 0)
			clk->prepared++;
		mutex_unlock(&clk->mutex);
	}

	return ret;
}

I'm afraid this will hide enable/disable imbalances on some targets and
then expose them on others. Maybe its not a big problem though since
this also elegantly handles the root(s) of the tree.

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.