summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2024-09-19 10:16:04 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-09-19 10:16:04 +0300
commit84bbfe6b6435658132df2880258d34babe46d3e0 (patch)
tree3066cce5c7ab4daa2268230204f1124f4ce3faeb /Documentation
parent2a17bb8c204f2b6461524a1b52ace2dbe097eaf7 (diff)
parent837acb691c844d0525f4ac86f2a2ce55a9706908 (diff)
downloadlinux-84bbfe6b6435658132df2880258d34babe46d3e0.tar.xz
Merge tag 'platform-drivers-x86-v6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform drivers updates from Hans de Goede: - asus-wmi: Add support for vivobook fan profiles - dell-laptop: Add knobs to change battery charge settings - lg-laptop: Add operation region support - intel-uncore-freq: Add support for efficiency latency control - intel/ifs: Add SBAF test support - intel/pmc: Ignore all LTRs during suspend - platform/surface: Support for arm64 based Surface devices - wmi: Pass event data directly to legacy notify handlers - x86/platform/geode: switch GPIO buttons and LEDs to software properties - bunch of small cleanups, fixes, hw-id additions, etc. * tag 'platform-drivers-x86-v6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (65 commits) MAINTAINERS: adjust file entry in INTEL MID PLATFORM platform/x86: x86-android-tablets: Adjust Xiaomi Pad 2 bottom bezel touch buttons LED platform/mellanox: mlxbf-pmc: fix lockdep warning platform/x86/amd: pmf: Add quirk for TUF Gaming A14 platform/x86: touchscreen_dmi: add nanote-next quirk platform/x86: asus-wmi: don't fail if platform_profile already registered platform/x86: asus-wmi: add debug print in more key places platform/x86: intel_scu_wdt: Move intel_scu_wdt.h to x86 subfolder platform/x86: intel_scu_ipc: Move intel_scu_ipc.h out of arch/x86/include/asm MAINTAINERS: Add Intel MID section platform/x86: panasonic-laptop: Add support for programmable buttons platform/olpc: Remove redundant null pointer checks in olpc_ec_setup_debugfs() platform/x86: intel/pmc: Ignore all LTRs during suspend platform/x86: wmi: Call both legacy and WMI driver notify handlers platform/x86: wmi: Merge get_event_data() with wmi_get_notify_data() platform/x86: wmi: Remove wmi_get_event_data() platform/x86: wmi: Pass event data directly to legacy notify handlers platform/x86: thinkpad_acpi: Fix uninitialized symbol 's' warning platform/x86: x86-android-tablets: Fix spelling in the comments platform/x86: ideapad-laptop: Make the scope_guard() clear of its scope ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst59
-rw-r--r--Documentation/devicetree/bindings/platform/microsoft,surface-sam.yaml47
-rw-r--r--Documentation/devicetree/bindings/serial/serial.yaml2
3 files changed, 107 insertions, 1 deletions
diff --git a/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst b/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst
index 5ab3440e6cee..5151ec312dc0 100644
--- a/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst
+++ b/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst
@@ -113,3 +113,62 @@ to apply at each uncore* level.
Support for "current_freq_khz" is available only at each fabric cluster
level (i.e., in uncore* directory).
+
+Efficiency vs. Latency Tradeoff
+-------------------------------
+
+The Efficiency Latency Control (ELC) feature improves performance
+per watt. With this feature hardware power management algorithms
+optimize trade-off between latency and power consumption. For some
+latency sensitive workloads further tuning can be done by SW to
+get desired performance.
+
+The hardware monitors the average CPU utilization across all cores
+in a power domain at regular intervals and decides an uncore frequency.
+While this may result in the best performance per watt, workload may be
+expecting higher performance at the expense of power. Consider an
+application that intermittently wakes up to perform memory reads on an
+otherwise idle system. In such cases, if hardware lowers uncore
+frequency, then there may be delay in ramp up of frequency to meet
+target performance.
+
+The ELC control defines some parameters which can be changed from SW.
+If the average CPU utilization is below a user-defined threshold
+(elc_low_threshold_percent attribute below), the user-defined uncore
+floor frequency will be used (elc_floor_freq_khz attribute below)
+instead of hardware calculated minimum.
+
+Similarly in high load scenario where the CPU utilization goes above
+the high threshold value (elc_high_threshold_percent attribute below)
+instead of jumping to maximum uncore frequency, frequency is increased
+in 100MHz steps. This avoids consuming unnecessarily high power
+immediately with CPU utilization spikes.
+
+Attributes for efficiency latency control:
+
+``elc_floor_freq_khz``
+ This attribute is used to get/set the efficiency latency floor frequency.
+ If this variable is lower than the 'min_freq_khz', it is ignored by
+ the firmware.
+
+``elc_low_threshold_percent``
+ This attribute is used to get/set the efficiency latency control low
+ threshold. This attribute is in percentages of CPU utilization.
+
+``elc_high_threshold_percent``
+ This attribute is used to get/set the efficiency latency control high
+ threshold. This attribute is in percentages of CPU utilization.
+
+``elc_high_threshold_enable``
+ This attribute is used to enable/disable the efficiency latency control
+ high threshold. Write '1' to enable, '0' to disable.
+
+Example system configuration below, which does following:
+ * when CPU utilization is less than 10%: sets uncore frequency to 800MHz
+ * when CPU utilization is higher than 95%: increases uncore frequency in
+ 100MHz steps, until power limit is reached
+
+ elc_floor_freq_khz:800000
+ elc_high_threshold_percent:95
+ elc_high_threshold_enable:1
+ elc_low_threshold_percent:10
diff --git a/Documentation/devicetree/bindings/platform/microsoft,surface-sam.yaml b/Documentation/devicetree/bindings/platform/microsoft,surface-sam.yaml
new file mode 100644
index 000000000000..b33d26f15b2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/platform/microsoft,surface-sam.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/platform/microsoft,surface-sam.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Surface System Aggregator Module (SAM, SSAM)
+
+maintainers:
+ - Konrad Dybcio <konradybcio@kernel.org>
+
+description: |
+ Surface devices use a standardized embedded controller to let the
+ operating system interface with various hardware functions. The
+ specific functionalities are modeled as subdevices and matched on
+ five levels: domain, category, target, instance and function.
+
+properties:
+ compatible:
+ const: microsoft,surface-sam
+
+ interrupts:
+ maxItems: 1
+
+ current-speed: true
+
+required:
+ - compatible
+ - interrupts
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ uart {
+ embedded-controller {
+ compatible = "microsoft,surface-sam";
+
+ interrupts-extended = <&tlmm 91 IRQ_TYPE_EDGE_RISING>;
+
+ pinctrl-0 = <&ssam_state>;
+ pinctrl-names = "default";
+
+ current-speed = <4000000>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/serial/serial.yaml b/Documentation/devicetree/bindings/serial/serial.yaml
index 30c85768d980..6aa9cfae417b 100644
--- a/Documentation/devicetree/bindings/serial/serial.yaml
+++ b/Documentation/devicetree/bindings/serial/serial.yaml
@@ -88,7 +88,7 @@ properties:
TX FIFO threshold configuration (in bytes).
patternProperties:
- "^(bluetooth|bluetooth-gnss|gnss|gps|mcu|onewire)$":
+ "^(bluetooth|bluetooth-gnss|embedded-controller|gnss|gps|mcu|onewire)$":
if:
type: object
then: