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-rw-r--r--Documentation/ABI/testing/sysfs-class-firmware-attributes30
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diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
index f205d39409..9c82c7b42f 100644
--- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
+++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
@@ -383,6 +383,36 @@ Description:
Note that any changes to this attribute requires a reboot
for changes to take effect.
+What: /sys/class/firmware-attributes/*/attributes/save_settings
+Date: August 2023
+KernelVersion: 6.6
+Contact: Mark Pearson <mpearson-lenovo@squebb.ca>
+Description:
+ On Lenovo platforms there is a limitation in the number of times an attribute can be
+ saved. This is an architectural limitation and it limits the number of attributes
+ that can be modified to 48.
+ A solution for this is instead of the attribute being saved after every modification,
+ to allow a user to bulk set the attributes, and then trigger a final save. This allows
+ unlimited attributes.
+
+ Read the attribute to check what save mode is enabled (single or bulk).
+ E.g:
+ # cat /sys/class/firmware-attributes/thinklmi/attributes/save_settings
+ single
+
+ Write the attribute with 'bulk' to enable bulk save mode.
+ Write the attribute with 'single' to enable saving, after every attribute set.
+ The default setting is single mode.
+ E.g:
+ # echo bulk > /sys/class/firmware-attributes/thinklmi/attributes/save_settings
+
+ When in bulk mode write 'save' to trigger a save of all currently modified attributes.
+ Note, once a save has been triggered, in bulk mode, attributes can no longer be set and
+ will return a permissions error. This is to prevent users hitting the 48+ save limitation
+ (which requires entering the BIOS to clear the error condition)
+ E.g:
+ # echo save > /sys/class/firmware-attributes/thinklmi/attributes/save_settings
+
What: /sys/class/firmware-attributes/*/attributes/debug_cmd
Date: July 2021
KernelVersion: 5.14