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
  ...

1 files changed, 59 insertions, 0 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