man: add few mentions about MODPROBE_OPTIONS

The environment variable may alter config file ordering, so mention it
in the man page.

In addition, highlight that the format is intentionally undocumented
since the use by third parties is discouraged.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

diff --git a/man/modprobe.8.scd b/man/modprobe.8.scd
index b47908bdf63fcb92774424c5857f38166a70c9ad..321fa59caec9fd09f3cafe2a1ed5954775fe1f55 100644 (file)
--- a/man/modprobe.8.scd
+++ b/man/modprobe.8.scd
@@ -192,8 +192,12 @@ database.
 
 # ENVIRONMENT
 
-The MODPROBE_OPTIONS environment variable can also be used to pass arguments to
-*modprobe*.
+The MODPROBE_OPTIONS environment variable can also be used to pass command line
+arguments to *modprobe*. The format is intentionally left undocumented, since
+the use by third-party tools and scripts is discouraged.
+
+The environment variable originates with the implementation of the install
+rules.
 
 # COPYRIGHT
 

diff --git a/man/modprobe.d.5.scd b/man/modprobe.d.5.scd
index 823ba62812cf61202e44055c3a7f008953e2cbc8..b7b19427bdab31f96c3812f684f90a92c4286c98 100644 (file)
--- a/man/modprobe.d.5.scd
+++ b/man/modprobe.d.5.scd
@@ -49,6 +49,9 @@ directory they reside in. Configuration files can either be completely replaced
 priority) or partially replaced (by having a configuration file that is ordered
 later).
 
+NOTE: The configuration directories may be altered via the MODPROBE_OPTIONS
+environment variable. See the ENVIRONMENT section in *modprobe*(8).
+
 # COMMANDS
 
 alias _wildcard_ _modulename_