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

[Stephen Boyd]

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.