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Diffstat (limited to 'Documentation/admin-guide/laptops/thinkpad-acpi.rst')
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index adea0bf2acc5..822907dcc845 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -49,6 +49,7 @@ detailed description): - Fan control and monitoring: fan speed, fan enable/disable - WAN enable and disable - UWB enable and disable + - LCD Shadow (PrivacyGuard) enable and disable A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1409,6 +1410,28 @@ Sysfs notes Documentation/driver-api/rfkill.rst for details. +LCD Shadow control +------------------ + +procfs: /proc/acpi/ibm/lcdshadow + +Some newer T480s and T490s ThinkPads provide a feature called +PrivacyGuard. By turning this feature on, the usable vertical and +horizontal viewing angles of the LCD can be limited (as if some privacy +screen was applied manually in front of the display). + +procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo '0' >/proc/acpi/ibm/lcdshadow + echo '1' >/proc/acpi/ibm/lcdshadow + +The first command ensures the best viewing angle and the latter one turns +on the feature, restricting the viewing angles. + + EXPERIMENTAL: UWB ----------------- |