[PATCH] thermal/core: Make 'forced_passive' as obsolete candidate

From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: daniel.lezcano@linaro.org, rui.zhang@intel.com
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, amitk@kernel.org
Subject: [PATCH] thermal/core: Make 'forced_passive' as obsolete candidate
Date: Tue,  8 Dec 2020 16:30:43 +0100	[thread overview]
Message-ID: <20201208153046.297456-1-daniel.lezcano@linaro.org> (raw)

The passive file in sysfs forces the usage of a passive trip point set
by the userspace when a broken BIOS does not provide the mitigation
temperature for such thermal zone. The hardware evolved a lot since
2008 as a good thermal management is no longer an option.

Linux on the other side also provides now a way to load fixed ACPI
table via the option ACPI_TABLE_UPGRADE, so additionnal trip point
could be added there.

Set the option obsolete and plan to remove it, so the corresponding
code can be removed from the core code and allow more cleanups the
thermal framework deserves.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 Documentation/ABI/obsolete/sysfs-thermal-passive | 13 +++++++++++++
 drivers/thermal/thermal_sysfs.c                  |  2 ++
 2 files changed, 15 insertions(+)
 create mode 100644 Documentation/ABI/obsolete/sysfs-thermal-passive

diff --git a/Documentation/ABI/obsolete/sysfs-thermal-passive b/Documentation/ABI/obsolete/sysfs-thermal-passive
new file mode 100644
index 000000000000..2510724cc165
--- /dev/null
+++ b/Documentation/ABI/obsolete/sysfs-thermal-passive
@@ -0,0 +1,13 @@
+What:		/sys/class/thermal/thermal_zone*/passive
+Date:		December 2008
+KernelVersion:	2.6.28
+Contact:	Daniel Lezcano <daniel.lezcano@linaro.org>
+Description:
+
+  The passive file in sysfs forces the usage of a passive trip point
+  set by the userspace when a broken BIOS does not provide the
+  mitigation temperature for such thermal zone. However, the Linux
+  kernel evolved a lot since 2008 as well as the hardware and it is
+  able to manage correctly the thermal envelope. It does also provide
+  a way to load fixed ACPI table via the option ACPI_TABLE_UPGRADE, so
+  additionnal trip point could be added there.
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 0866e949339b..578099b520b1 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -232,6 +232,8 @@ passive_store(struct device *dev, struct device_attribute *attr,
 	if (state && state < 1000)
 		return -EINVAL;
 
+	pr_warn("%s: Consider the 'passive' option obsolete\n", tz->type);
+
 	if (state && !tz->forced_passive) {
 		if (!tz->passive_delay)
 			tz->passive_delay = 1000;
-- 
2.25.1

