[PATCH] pwm: core: Zero-initialize the temp state

[Munehisa Kamata <kamatam@amazon.com>]

Zero-initialize the on-stack structure to avoid unexpected behaviors. Some
drivers may not set or initialize all the values in pwm_state through their
.get_state() callback and therefore some random values may remain there and
be set into pwm->state eventually.

This actually caused regression on ODROID-N2+ as reported in [1]; kernel
fails to boot due to random panic or hang-up.

[1] https://forum.odroid.com/viewtopic.php?f=177&t=46360

Fixes: c73a3107624d ("pwm: Handle .get_state() failures")
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
---
 drivers/pwm/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index e01147f66e15..6eac8022a2c2 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -117,6 +117,7 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
 	if (pwm->chip->ops->get_state) {
 		struct pwm_state state;
 
+		memset(&state, 0, sizeof(struct pwm_state));
 		err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
 		trace_pwm_get(pwm, &state, err);
 
-- 
2.25.1