The change intends to centralize allocation of clock's clk_core
parents array on clock registration, originally is done from multiple
places:
* __clk_init()
* __clk_init_parent()
* clk_fetch_parent_index()
The original approach historically was needed, but at the moment
all assumptions supporting it are wrong:
1) GFP_KERNEL heap is available at the time of a clock registration,
for example it is used to dynamically allocate struct clk_core,
clock name and clock parent names, if allocation fails, return
-ENOMEM as usual instead of repeating attempts to allocate the
array in future,
2) due to the layering scheme clk_core parents can not be defined
statically by the drivers, instead the drivers provide string
arrays of clock parent names and clock parents for a lookup array
are always obtained from that data.
To ensure that there is no need to check for allocated status of the
parent lookup table and/or allocate the table from other places within
the common clock framework, don't register a clock, if there is no
enough memory.
Signed-off-by: Vladimir Zapolskiy <v...@mleia.com>
---
drivers/clk/clk.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 129ac0a..2fb0dae 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2371,27 +2371,25 @@ static int __clk_init(struct device *dev, struct clk
*clk_user)
/*
* Allocate an array of struct clk *'s to avoid unnecessary string
- * look-ups of clk's possible parents. This can fail for clocks passed
- * in to clk_init during early boot; thus any access to core->parents[]
- * must always check for a NULL pointer and try to populate it if
- * necessary.
- *
- * If core->parents is not NULL we skip this entire block. This allows
- * for clock drivers to statically initialize core->parents.
+ * look-ups of clk's possible parents.
*/
- if (core->num_parents > 1 && !core->parents) {
+ if (core->num_parents > 1) {
core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
GFP_KERNEL);
+ if (!core->parents) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
/*
* clk_core_lookup returns NULL for parents that have not been
* clk_init'd; thus any access to clk->parents[] must check
* for a NULL pointer. We can always perform lazy lookups for
* missing parents later on.
*/
- if (core->parents)
- for (i = 0; i < core->num_parents; i++)
- core->parents[i] =
- clk_core_lookup(core->parent_names[i]);
+ for (i = 0; i < core->num_parents; i++)
+ core->parents[i] =
+ clk_core_lookup(core->parent_names[i]);
}
core->parent = __clk_init_parent(core);
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-clk" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
