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);