Re: [PATCH v2] thermal/core: Clear all mitigation when thermal zone is disabled
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2021-12-30 16:10:00
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On Wed, Dec 29, 2021 at 8:03 AM Manaf Meethalavalappu Pallikunhi [off-list ref] wrote:
Whenever a thermal zone is in trip violated state, there is a chance that the same thermal zone mode can be disabled either via thermal core API or via thermal zone sysfs. Once it is disabled, the framework bails out any re-evaluation of thermal zone. It leads to a case where if it is already in mitigation state, it will stay the same state until it is re-enabled.
You seem to be arguing that disabling a thermal zone should prevent it from throttling anything, which is reasonable, but I'm not sure if the change below is sufficient for that.
quoted hunk ↗ jump to hunk
To avoid above mentioned issue, on thermal zone disable request reset thermal zone and clear mitigation for each trip explicitly. Signed-off-by: Manaf Meethalavalappu Pallikunhi <redacted> --- drivers/thermal/thermal_core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 51374f4..5f4e35b 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c@@ -427,6 +427,7 @@ static int thermal_zone_device_set_mode(struct thermal_zone_device *tz, enum thermal_device_mode mode) { int ret = 0; + int trip;
This can be declared in the block in which it is used.
quoted hunk ↗ jump to hunk
mutex_lock(&tz->lock);@@ -449,8 +450,14 @@ static int thermal_zone_device_set_mode(struct thermal_zone_device *tz, if (mode == THERMAL_DEVICE_ENABLED)
The coding style asks for braces here if they are used after the else.
thermal_notify_tz_enable(tz->id);
- else
+ else {
+ /* make sure all previous throttlings are cleared */
+ thermal_zone_device_init(tz);
+ for (trip = 0; trip < tz->trips; trip++)
+ handle_thermal_trip(tz, trip);So I'm not sure if this makes the throttling go away in all cases (eg. what if the current temperature is still above the given trip at this point?).
+
thermal_notify_tz_disable(tz->id);
+ }
return ret;
}