Diffstat (limited to 'Documentation/usb/usbmon.txt')
1 files changed, 7 insertions, 5 deletions
diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt
index 2917ce4ffdc4..270481906dc8 100644
@@ -34,11 +34,12 @@ if usbmon is built into the kernel.
Verify that bus sockets are present.
# ls /sys/kernel/debug/usbmon
-0s 0t 0u 1s 1t 1u 2s 2t 2u 3s 3t 3u 4s 4t 4u
+0s 0u 1s 1t 1u 2s 2t 2u 3s 3t 3u 4s 4t 4u
-Now you can choose to either use the sockets numbered '0' (to capture packets on
-all buses), and skip to step #3, or find the bus used by your device with step #2.
+Now you can choose to either use the socket '0u' (to capture packets on all
+buses), and skip to step #3, or find the bus used by your device with step #2.
+This allows to filter away annoying devices that talk continuously.
2. Find which bus connects to the desired device
@@ -99,8 +100,9 @@ on the event type, but there is a set of words, common for all types.
Here is the list of words, from left to right:
-- URB Tag. This is used to identify URBs is normally a kernel mode address
- of the URB structure in hexadecimal.
+- URB Tag. This is used to identify URBs, and is normally an in-kernel address
+ of the URB structure in hexadecimal, but can be a sequence number or any
+ other unique string, within reason.
- Timestamp in microseconds, a decimal number. The timestamp's resolution
depends on available clock, and so it can be much worse than a microsecond