diff options
| author | Dong Aisheng <aisheng.dong@freescale.com> | 2015-04-15 22:26:36 +0800 |
|---|---|---|
| committer | Stephen Boyd <sboyd@codeaurora.org> | 2015-05-06 16:58:53 -0700 |
| commit | d2a5d46b167a9a8231264daf80165b739aecf1d7 (patch) | |
| tree | aacc2fe63fde97d4263fbb9a2487a6dbc3fc01e3 /drivers/clk | |
| parent | 5d45ed8f5bfaeaf50576b8d663796ee905ccf2a0 (diff) | |
clk: add missing lock when call clk_core_enable in clk_set_parent
Before commit 035a61c314eb ("clk: Make clk API return per-user
struct clk instances") we acquired the enable_lock in
__clk_set_parent_{before,after}() by means of calling
clk_enable(). After commit 035a61c314eb we use clk_core_enable()
in place of the clk_enable(), and clk_core_enable() doesn't
acquire the enable_lock. This opens up a race condition between
clk_set_parent() and clk_enable(). Fix it.
Fixes: 035a61c314eb ("clk: Make clk API return per-user struct clk instances")
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/clk.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 459ce9da13e0..5b0f41868b42 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1475,8 +1475,10 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *clk, */ if (clk->prepare_count) { clk_core_prepare(parent); + flags = clk_enable_lock(); clk_core_enable(parent); clk_core_enable(clk); + clk_enable_unlock(flags); } /* update the clk tree topology */ @@ -1491,13 +1493,17 @@ static void __clk_set_parent_after(struct clk_core *core, struct clk_core *parent, struct clk_core *old_parent) { + unsigned long flags; + /* * Finish the migration of prepare state and undo the changes done * for preventing a race with clk_enable(). */ if (core->prepare_count) { + flags = clk_enable_lock(); clk_core_disable(core); clk_core_disable(old_parent); + clk_enable_unlock(flags); clk_core_unprepare(old_parent); } } @@ -1525,8 +1531,10 @@ static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent, clk_enable_unlock(flags); if (clk->prepare_count) { + flags = clk_enable_lock(); clk_core_disable(clk); clk_core_disable(parent); + clk_enable_unlock(flags); clk_core_unprepare(parent); } return ret; |