6.8-stable review patch. If anyone has any objections, please let me know.
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From: Nikita Travkin nikita@trvn.ru
[ Upstream commit da781936e7c301e6197eb6513775748e79fb2575 ]
IPA probe function was recently refactored to perform extra error checks and make sure the thermal zone has trip points necessary for the IPA operation. With this change, if a thermal zone is probed such that it has no trip points that IPA can use, IPA will fail and the TZ won't be created. This is the case if a platform defines a TZ without cooling devices and only with "hot"/"critical" trip points, often found on some Qualcomm devices [1].
Documentation across IPA code (notably get_governor_trips() kerneldoc) suggests that IPA is supposed to handle such TZ even if it won't actually do anything.
This commit partially reverts the previous change to allow IPA to bind to such "empty" thermal zones.
Fixes: e83747c2f8e3 ("thermal: gov_power_allocator: Set up trip points earlier") Link: arch/arm64/boot/dts/qcom/sc7180.dtsi#n4776 # [1] Signed-off-by: Nikita Travkin nikita@trvn.ru Reviewed-by: Lukasz Luba lukasz.luba@arm.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thermal/gov_power_allocator.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index 207a6a3936b54..38581583ad289 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -679,11 +679,6 @@ static int power_allocator_bind(struct thermal_zone_device *tz) return -ENOMEM;
get_governor_trips(tz, params); - if (!params->trip_max) { - dev_warn(&tz->device, "power_allocator: missing trip_max\n"); - kfree(params); - return -EINVAL; - }
ret = check_power_actors(tz, params); if (ret < 0) { @@ -712,9 +707,10 @@ static int power_allocator_bind(struct thermal_zone_device *tz) if (!tz->tzp->sustainable_power) dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n");
- estimate_pid_constants(tz, tz->tzp->sustainable_power, - params->trip_switch_on, - params->trip_max->temperature); + if (params->trip_max) + estimate_pid_constants(tz, tz->tzp->sustainable_power, + params->trip_switch_on, + params->trip_max->temperature);
reset_pid_controller(params);