shill: add documentation for ff_debug levels
BUG=chromium-os:38692
TEST=manual (see below)
Manual Testing
--------------
- ff_debug --help
verify that examples of ff_debug --level are shown
- ff_debug --level -4
verify that debug level has changed
Change-Id: I94e88cb23df9ff46ff3f42f3efd948ac8b3f7b55
Reviewed-on: https://gerrit.chromium.org/gerrit/42778
Reviewed-by: Wade Guthrie <wdg@chromium.org>
Commit-Queue: mukesh agrawal <quiche@chromium.org>
Tested-by: mukesh agrawal <quiche@chromium.org>
diff --git a/bin/ff_debug b/bin/ff_debug
index 1ab74d4..f9eeb63 100755
--- a/bin/ff_debug
+++ b/bin/ff_debug
@@ -27,14 +27,27 @@
<debug_tag> can be listed using the --list_valid_tags
- eg: ff_debug network+wifi
+ e.g.: ff_debug network+wifi
Sets debug tags to network and wifi
- eg: ff_debug +network-service
+ e.g.: ff_debug +network-service
Adds network and removes service tags from the existing debug settings
--list_valid_tags : Displays all valid tags
--level: Displays or sets current debug level for logging
+ All messages at, or above, the current log level are logged. Normal log
+ levels range from 4 (LOG_FATAL) to 0 (LOG_INFO). In addition VERBOSE log
+ levels are available starting at -1.
+
+ e.g.: ff_debug --level 4
+ Logs only FATAL messages.
+ e.g.: ff_debug --level 0
+ Logs INFO, WARNING, ERROR, ERROR_REPORT, and FATAL messages.
+ e.g.: ff_debug --level -4
+ Logs everything that "--level 0" does, plus SLOG(<tag>, <n>) messages,
+ where <tag> has been enabled for logging, and <n> <= 4. (NOTE: you must
+ negate SLOG levels for use with ff_debug. In this example, SLOG(<tag>, 4)
+ maps to "--level -4".)
--reset : Removes all tagging