From db0aeb4f074f7023da26fb65078197c39590346b Mon Sep 17 00:00:00 2001 From: Matti Vaittinen Date: Thu, 3 Jun 2021 08:41:03 +0300 Subject: thermal: Use generic HW-protection shutdown API The hardware shutdown function was exported from kernel/reboot for other subsystems to use. Logic is copied from the thermal_core. The protection mutex is replaced by an atomic_t to allow calls also from an IRQ context. Also the WARN() was replaced by pr_emerg() based on discussions here: https://lore.kernel.org/lkml/YJuPwAZroVZ%2Fw633@alley/ and here: https://lore.kernel.org/linux-iommu/20210331093104.383705-4-geert+renesas@glider.be/ Use the exported API instead of implementing own just for the thermal_core. Signed-off-by: Matti Vaittinen Acked-by: Daniel Lezcano Link: https://lore.kernel.org/r/5531e89d9e710f5d10e7cdce3ee58957335b9e03.1622628333.git.matti.vaittinen@fi.rohmeurope.com Signed-off-by: Mark Brown --- Documentation/driver-api/thermal/sysfs-api.rst | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) (limited to 'Documentation/driver-api') diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index 4b638c14bc16..c93fa5e961a0 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -740,21 +740,15 @@ possible. 5. thermal_emergency_poweroff ============================= -On an event of critical trip temperature crossing. Thermal framework -allows the system to shutdown gracefully by calling orderly_poweroff(). -In the event of a failure of orderly_poweroff() to shut down the system -we are in danger of keeping the system alive at undesirably high -temperatures. To mitigate this high risk scenario we program a work -queue to fire after a pre-determined number of seconds to start -an emergency shutdown of the device using the kernel_power_off() -function. In case kernel_power_off() fails then finally -emergency_restart() is called in the worst case. +On an event of critical trip temperature crossing the thermal framework +shuts down the system by calling hw_protection_shutdown(). The +hw_protection_shutdown() first attempts to perform an orderly shutdown +but accepts a delay after which it proceeds doing a forced power-off +or as last resort an emergency_restart. The delay should be carefully profiled so as to give adequate time for -orderly_poweroff(). In case of failure of an orderly_poweroff() the -emergency poweroff kicks in after the delay has elapsed and shuts down -the system. +orderly poweroff. -If set to 0 emergency poweroff will not be supported. So a carefully -profiled non-zero positive value is a must for emergency poweroff to be -triggered. +If the delay is set to 0 emergency poweroff will not be supported. So a +carefully profiled non-zero positive value is a must for emergency +poweroff to be triggered. -- cgit v1.2.3