[PATCH 4.19 046/267] PM: runtime: clk: Fix clk_pm_runtime_get() error path

Greg Kroah-Hartman
2020-06-19T14:55:08Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

commit 64c7d7ea22d86cacb65d0c097cc447bc0e6d8abd upstream.

clk_pm_runtime_get() assumes that the PM-runtime usage counter will
be dropped by pm_runtime_get_sync() on errors, which is not the case,
so PM-runtime references to devices acquired by the former are leaked
on errors returned by the latter.

Fix this by modifying clk_pm_runtime_get() to drop the reference if
pm_runtime_get_sync() returns an error.

Fixes: 9a34b45397e5 clk: Add support for runtime PM
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/clk/clk.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -101,7 +101,11 @@ static int clk_pm_runtime_get(struct clk
return 0;

ret = pm_runtime_get_sync(core->dev);
- return ret < 0 ? ret : 0;
+ if (ret < 0) {
+ pm_runtime_put_noidle(core->dev);
+ return ret;
+ }
+ return 0;
}

static void clk_pm_runtime_put(struct clk_core *core)