Quoting Rajagopal Venkat (2013-01-08 22:29:48)
while reparenting a clock, NULL check is done for clock in consideration and its new parent. So re-check is not required. If done, else part becomes unreachable.
Signed-off-by: Rajagopal Venkat rajagopal.venkat@linaro.org
drivers/clk/clk.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 251e45d..1c4097c 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1040,7 +1040,6 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) { #ifdef CONFIG_COMMON_CLK_DEBUG struct dentry *d;
struct dentry *new_parent_d;#endif if (!clk || !new_parent) @@ -1048,22 +1047,14 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) hlist_del(&clk->child_node);
if (new_parent)hlist_add_head(&clk->child_node, &new_parent->children);elsehlist_add_head(&clk->child_node, &clk_orphan_list);
hlist_add_head(&clk->child_node, &new_parent->children);
Rajagopal,
You found a bug, but not the right one :)
This change would result in never moving a clock into the orphan list if the parent is missing. The right thing to do is to allow the operation to succeed and migrate this clock into the orphan list. In keeping with the clk.h api we need to treat struct clk new_parent as an opaque cookie and not care whether or not it is NULL.
Untested patch below fixes the real bug:
From a4d56e3ee51452366365749873710e16631e9de7 Mon Sep 17 00:00:00 2001 From: Mike Turquette mturquette@linaro.org Date: Tue, 15 Jan 2013 14:39:06 -0800 Subject: [PATCH] clk: allow re-parenting to NULL clks
__clk_reparent presently bails early if the new parent of a clk is NULL. This is wrong and prevents dynamically migrating clocks into the orphan list. The fix is to remove the NULL pointer check for new_parent in __clk_parent.
Signed-off-by: Mike Turquette mturquette@linaro.org --- drivers/clk/clk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 593a2e4..f056230 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1186,7 +1186,7 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) struct dentry *new_parent_d; #endif
- if (!clk || !new_parent) + if (!clk) return;
hlist_del(&clk->child_node);