From 8f6fafa9610dd8b0e0060eea9401f7bd64f4942b Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Thu, 21 Jan 2021 16:48:55 +0800 Subject: [PATCH] thermal/core: Emit a warning if the thermal zone is updated without ops BugLink: https://bugs.launchpad.net/bugs/1906168 The actual code is silently ignoring a thermal zone update when a driver is requesting it without a get_temp ops set. That looks not correct, as the caller should not have called this function if the thermal zone is unable to read the temperature. That makes the code less robust as the check won't detect the driver is inconsistently using the thermal API and that does not help to improve the framework as these circumvolutions hide the problem at the source. In order to detect the situation when it happens, let's add a warning when the update is requested without the get_temp() ops set. Any warning emitted will have to be fixed at the source of the problem: the caller must not call thermal_zone_device_update if there is not get_temp callback set. Cc: Thara Gopinath Cc: Amit Kucheria Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Lezcano Reviewed-by: Lukasz Luba Link: https://lore.kernel.org/r/20201210121514.25760-1-daniel.lezcano@linaro.org (cherry picked from commit 433178e75834dc35f1ae79b56ec2cf396f2c6f3c) Signed-off-by: Kai-Heng Feng Signed-off-by: Timo Aaltonen --- drivers/thermal/thermal_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index c6d74bc1c90bb..d819c98ebb9db 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -553,7 +553,8 @@ void thermal_zone_device_update(struct thermal_zone_device *tz, if (atomic_read(&in_suspend)) return; - if (!tz->ops->get_temp) + if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without " + "'get_temp' ops set\n", __func__)) return; update_temperature(tz);