[PATCH v4 6/6] clk: Add floor and ceiling constraints to clock rates

Stephen Warren swarren at wwwdotorg.org
Tue Jul 22 10:51:32 PDT 2014

On 07/17/2014 08:13 AM, Tomeu Vizoso wrote:
> Adds a way for clock consumers to set maximum and minimum rates. This can be
> used for thermal drivers to set ceiling rates, or by misc. drivers to set
> floor rates to assure a minimum performance level.

> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c

> +struct rate_constraint {
> +	struct hlist_node	node;
> +	const char		*dev_id;
> +	const char		*con_id;
> +	enum constraint_type	type;
> +	unsigned long		rate;
> +};

I would personally still prefer either:

a) The struct rate_constraints be stored in struct clk rather than
struct clk_core, so they're stored in the container that "set" the
constraints. This would mean iterating over a struct clk_core's
associated struct clks, then iterating over the struct rate_constraints
within each struct clk.


b) struct rate_constraint to contain a pointer to the struct clk that
created the constraint, rather than copying the dev_id/con_id from that
struct clk into the struct rate_constraint.

With either of those changes, the constraints are directly associated
with the clock client object that created the constraint much better
than right now, where the matching is only because the struct clk and
struct rate_constraint "happen to" have the same dev_id/con_id values.

Still, this is a pretty minor issue, and overall this series looks
reasonable to me at a quick look.

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