diff options
| author | Pete Zaitcev <zaitcev@redhat.com> | 2005-06-25 14:32:59 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-07-12 11:52:55 -0700 |
| commit | ae0d6cceb20eec57e7196c22999c62c465ffd5bf (patch) | |
| tree | ba6b822e410af8621dc6f42bf0792b9eece2bbc6 /Documentation/usb | |
| parent | ead99eb00190a274e3b3666ecd431be12c2b7888 (diff) | |
[PATCH] USB: Patch to make usbmon to print control setup packets
Make usbmon to print Setup packets of Control transfers. This is useful
when debugging enumeration issues.
This is a change to the trace format which is not fully compatible.
A parser has to look at the data length word now. If that word is
a character like 's', read setup packet before proceeding with data.
I decided not to bump the API tag for this because not many such
parsers exist at this point.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/usbmon.txt | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt index 2f8431f92b77..f1896ee3bb2a 100644 --- a/Documentation/usb/usbmon.txt +++ b/Documentation/usb/usbmon.txt @@ -101,6 +101,13 @@ Here is the list of words, from left to right: 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. + In case of a setup packet, it contains a Setup Tag. If scripts read a number + in this field, the proceed to read Data Length. Otherwise, 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. This is the actual length in the URB. - Data tag. The usbmon may not always capture data, even if length is nonzero. Only if tag is '=', the data words are present. @@ -125,25 +132,31 @@ class ParsedLine { 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++) { - 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++; } } } } -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: -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: |