--- zzzz-none-000/linux-3.10.107/Documentation/dynamic-debug-howto.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/dynamic-debug-howto.txt	2021-02-04 17:41:59.000000000 +0000
@@ -108,6 +108,12 @@
 
   ~# cat query-batch-file > <debugfs>/dynamic_debug/control
 
+A another way is to use wildcard. The match rule support '*' (matches
+zero or more characters) and '?' (matches exactly one character).For
+example, you can match all usb drivers:
+
+  ~# echo "file drivers/usb/* +p" > <debugfs>/dynamic_debug/control
+
 At the syntactical level, a command comprises a sequence of match
 specifications, followed by a flags change specification.
 
@@ -279,7 +285,7 @@
 
 - modules do not need to define it explicitly
 - every module gets it tacitly, whether they use pr_debug or not
-- it doesnt appear in /sys/module/$module/parameters/
+- it doesn't appear in /sys/module/$module/parameters/
   To see it, grep the control file, or inspect /proc/cmdline.
 
 For CONFIG_DYNAMIC_DEBUG kernels, any settings given at boot-time (or
@@ -315,6 +321,9 @@
 nullarbor:~ # echo -n 'format "nfsd: READ" +p' >
 				<debugfs>/dynamic_debug/control
 
+// enable messages in files of which the paths include string "usb"
+nullarbor:~ # echo -n '*usb* +p' > <debugfs>/dynamic_debug/control
+
 // enable all messages
 nullarbor:~ # echo -n '+p' > <debugfs>/dynamic_debug/control