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authorRajendra Nayak <rnayak@ti.com>2012-07-03 12:11:41 +0530
committerMike Turquette <mturquette@linaro.org>2012-07-03 12:05:14 -0700
commit863b13271f1608ab3af6f7a371047d9a66693e38 (patch)
tree990c7445eff9b8da1e52eeca07101c13d928c920
parent6887a4131da3adaab011613776d865f4bcfb5678 (diff)
downloadlinux-stericsson-863b13271f1608ab3af6f7a371047d9a66693e38.tar.gz
clk: fix parent validation in __clk_set_parent()
The below commit introduced a bug in __clk_set_parent() which could cause it to *skip* the parent validation which makes sure the parent passed to the api is a valid one. commit 7975059db572eb47f0fb272a62afeae272a4b209 Author: Rajendra Nayak <rnayak@ti.com> Date: Wed Jun 6 14:41:31 2012 +0530 clk: Allow late cache allocation for clk->parents This was identified by the following compiler warning.. drivers/clk/clk.c: In function '__clk_set_parent': drivers/clk/clk.c:1083:5: warning: 'i' may be used uninitialized in this function [-Wuninitialized] .. as reported by Marc Kleine-Budde. There were various options discussed on how to fix this, one being initing 'i' to clk->num_parents, but the below approach was found to be more appropriate as it also makes the 'parent validation' code simpler to read. Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Rajendra Nayak <rnayak@ti.com> Signed-off-by: Mike Turquette <mturquette@linaro.org> Cc: stable@kernel.org
-rw-r--r--drivers/clk/clk.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index dcbe05616090..9a1eb0cfa95f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1067,26 +1067,24 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent)
old_parent = clk->parent;
- /* find index of new parent clock using cached parent ptrs */
- if (clk->parents)
- for (i = 0; i < clk->num_parents; i++)
- if (clk->parents[i] == parent)
- break;
- else
+ if (!clk->parents)
clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
GFP_KERNEL);
/*
- * find index of new parent clock using string name comparison
- * also try to cache the parent to avoid future calls to __clk_lookup
+ * find index of new parent clock using cached parent ptrs,
+ * or if not yet cached, use string name comparison and cache
+ * them now to avoid future calls to __clk_lookup.
*/
- if (i == clk->num_parents)
- for (i = 0; i < clk->num_parents; i++)
- if (!strcmp(clk->parent_names[i], parent->name)) {
- if (clk->parents)
- clk->parents[i] = __clk_lookup(parent->name);
- break;
- }
+ for (i = 0; i < clk->num_parents; i++) {
+ if (clk->parents && clk->parents[i] == parent)
+ break;
+ else if (!strcmp(clk->parent_names[i], parent->name)) {
+ if (clk->parents)
+ clk->parents[i] = __clk_lookup(parent->name);
+ break;
+ }
+ }
if (i == clk->num_parents) {
pr_debug("%s: clock %s is not a possible parent of clock %s\n",