fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / Documentation / usb / usbmon.txt

diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt
index 2f8431f..e65ec82 100644 (file)
--- a/Documentation/usb/usbmon.txt
+++ b/Documentation/usb/usbmon.txt
@@ -29,14 +29,13 @@ if usbmon is built into the kernel.
 
 # mount -t debugfs none_debugs /sys/kernel/debug
 # modprobe usbmon
 
 # mount -t debugfs none_debugs /sys/kernel/debug
 # modprobe usbmon

+#

 
 Verify that bus sockets are present.
 
 
 Verify that bus sockets are present.
 

-[root@lembas zaitcev]# ls /sys/kernel/debug/usbmon
+# ls /sys/kernel/debug/usbmon

 1s  1t  2s  2t  3s  3t  4s  4t
 1s  1t  2s  2t  3s  3t  4s  4t

-[root@lembas zaitcev]#
-
-# ls /sys/kernel
+#

 
 2. Find which bus connects to the desired device
 
 
 2. Find which bus connects to the desired device
 


@@ -76,7 +75,7 @@ that the file size is not excessive for your favourite editor.
 
 * Raw text data format
 
 
 * Raw text data format
 

-The '0t' type data consists of a stream of events, such as URB submission,
+The '1t' type data consists of a stream of events, such as URB submission,

 URB callback, submission error. Every event is a text line, which consists
 of whitespace separated words. The number of position of words may depend
 on the event type, but there is a set of words, common for all types.
 URB callback, submission error. Every event is a text line, which consists
 of whitespace separated words. The number of position of words may depend
 on the event type, but there is a set of words, common for all types.


@@ -97,13 +96,25 @@ Here is the list of words, from left to right:
     Zi Zo   Isochronous input and output
     Ii Io   Interrupt input and output
     Bi Bo   Bulk input and output
     Zi Zo   Isochronous input and output
     Ii Io   Interrupt input and output
     Bi Bo   Bulk input and output

-  Device address and Endpoint number are decimal numbers with leading zeroes
-  or 3 and 2 positions, correspondingly.
-- URB Status. This field makes no sense for submissions, but is present
-  to help scripts with parsing. In error case, it contains the error code.
-- Data Length. This is the actual length in the URB.
+  Device address and Endpoint number are 3-digit and 2-digit (respectively)
+  decimal numbers, with leading zeroes.
+- URB Status. In most cases, this field contains a number, sometimes negative,
+  which represents a "status" field of the URB. This field makes no sense for
+  submissions, but is present anyway to help scripts with parsing. When an
+  error occurs, the field contains the error code. In case of a submission of
+  a Control packet, this field contains a Setup Tag instead of an error code.
+  It is easy to tell whether the Setup Tag is present because it is never a
+  number. Thus if scripts find a number in this field, they proceed to read
+  Data Length. If they find something else, like a letter, they read the setup
+  packet before reading the Data Length.
+- Setup packet, if present, consists of 5 words: one of each for bmRequestType,
+  bRequest, wValue, wIndex, wLength, as specified by the USB Specification 2.0.
+  These words are safe to decode if Setup Tag was 's'. Otherwise, the setup
+  packet was present, but not captured, and the fields contain filler.
+- Data Length. For submissions, this is the requested length. For callbacks,
+  this is the actual length.

 - Data tag. The usbmon may not always capture data, even if length is nonzero.
 - Data tag. The usbmon may not always capture data, even if length is nonzero.

-  Only if tag is '=', the data words are present.
+  The data words are present only if this tag is '='.

 - Data words follow, in big endian hexadecimal format. Notice that they are
   not machine words, but really just a byte stream split into words to make
   it easier to read. Thus, the last word may contain from one to four bytes.
 - Data words follow, in big endian hexadecimal format. Notice that they are
   not machine words, but really just a byte stream split into words to make
   it easier to read. Thus, the last word may contain from one to four bytes.


@@ -125,25 +136,31 @@ class ParsedLine {
                        String data_str = st.nextToken();
                        int len = data_str.length() / 2;
                        int i;
                        String data_str = st.nextToken();
                        int len = data_str.length() / 2;
                        int i;

+                       int b;  // byte is signed, apparently?! XXX

                        for (i = 0; i < len; i++) {
                        for (i = 0; i < len; i++) {

-                               data[data_len] = Byte.parseByte(
-                                   data_str.substring(i*2, i*2 + 2),
-                                   16);
+                               // data[data_len] = Byte.parseByte(
+                               //     data_str.substring(i*2, i*2 + 2),
+                               //     16);
+                               b = Integer.parseInt(
+                                    data_str.substring(i*2, i*2 + 2),
+                                    16);
+                               if (b >= 128)
+                                       b *= -1;
+                               data[data_len] = (byte) b;

                                data_len++;
                        }
                }
        }
 }
 
                                data_len++;
                        }
                }
        }
 }
 

-This format is obviously deficient. For example, the setup packet for control
-transfers is not delivered. This will change in the future.
+This format may be changed in the future.

 
 Examples:
 
 
 Examples:
 

-An input control transfer to get a port status:
+An input control transfer to get a port status.

 
 

-d74ff9a0 2640288196 S Ci:001:00 -115 4 <
-d74ff9a0 2640288202 C Ci:001:00 0 4 = 01010100
+d5ea89a0 3575914555 S Ci:001:00 s a3 00 0000 0003 0004 4 <
+d5ea89a0 3575914560 C Ci:001:00 0 4 = 01050000

 
 An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
 to a storage device at address 5:
 
 An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
 to a storage device at address 5: