Re: [PATCH v2 1/2] clk: track the orphan status of clocks and their children

From: Stephen Boyd
Date: Mon Apr 20 2015 - 18:29:52 EST


On 04/12/15 04:37, Heiko Stübner wrote:
> While children of orphan clocks are not carried in the orphan-list itself,
> they're nevertheless orphans in their own right as they also don't have an
> input-rate available. To ease tracking if a clock is an orphan or has an
> orphan in its parent path introduce an orphan field into struct clk and
> update it and the fields in child-clocks when a clock gets added or removed
> from the orphan-list.
>
> Suggested-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>

Just nitpicks. Otherwise it looks good to me.

> ---
> drivers/clk/clk.c | 33 ++++++++++++++++++++++++++++++---
> 1 file changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index f85c8e2..a9fa5ab 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -62,6 +62,7 @@ struct clk_core {
> struct clk_core *new_parent;
> struct clk_core *new_child;
> unsigned long flags;
> + bool orphan;
> unsigned int enable_count;
> unsigned int prepare_count;
> unsigned long accuracy;
> @@ -1433,18 +1434,40 @@ static int clk_fetch_parent_index(struct clk_core *clk,
> return -EINVAL;
> }
>
> +/*
> + * Update the orphan status of @clk and all its children.
> + */
> +static void clk_update_orphan_status(struct clk_core *clk, int is_orphan)

Please s/clk/core/ here because it's a new function (yeah we've been
slow and haven't updated the whole file to do this consistently). Also
use bool for is_orphan.

> +{
> + struct clk_core *child;
> +
> + clk->orphan = is_orphan;
> +
> + hlist_for_each_entry(child, &clk->children, child_node)
> + clk_update_orphan_status(child, is_orphan);
> +}
> +
> static void clk_reparent(struct clk_core *clk, struct clk_core *new_parent)
> {
> + bool was_orphan = clk->orphan;
> +
> hlist_del(&clk->child_node);
>
> if (new_parent) {
> + bool becomes_orphan = new_parent->orphan;
> +
> /* avoid duplicate POST_RATE_CHANGE notifications */
> if (new_parent->new_child == clk)
> new_parent->new_child = NULL;
>
> hlist_add_head(&clk->child_node, &new_parent->children);
> +
> + if (was_orphan != becomes_orphan)
> + clk_update_orphan_status(clk, becomes_orphan);
> } else {
> hlist_add_head(&clk->child_node, &clk_orphan_list);
> + if (!was_orphan)
> + clk_update_orphan_status(clk, 1);

Please use true here.

> }
>
> clk->parent = new_parent;
> @@ -2348,13 +2371,17 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
> * clocks and re-parent any that are children of the clock currently
> * being clk_init'd.
> */
> - if (clk->parent)
> + if (clk->parent) {
> hlist_add_head(&clk->child_node,
> &clk->parent->children);
> - else if (clk->flags & CLK_IS_ROOT)
> + clk->orphan = clk->parent->orphan;
> + } else if (clk->flags & CLK_IS_ROOT) {
> hlist_add_head(&clk->child_node, &clk_root_list);
> - else
> + clk->orphan = 0;
> + } else {
> hlist_add_head(&clk->child_node, &clk_orphan_list);
> + clk->orphan = 1;

Please use true/false here.

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