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authorPete Zaitcev <zaitcev@redhat.com>2005-06-25 17:32:59 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2005-07-12 14:52:55 -0400
commitae0d6cceb20eec57e7196c22999c62c465ffd5bf (patch)
treeba6b822e410af8621dc6f42bf0792b9eece2bbc6 /Documentation/usb/usbmon.txt
parentead99eb00190a274e3b3666ecd431be12c2b7888 (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/usbmon.txt')
-rw-r--r--Documentation/usb/usbmon.txt29
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:
101 or 3 and 2 positions, correspondingly. 101 or 3 and 2 positions, correspondingly.
102- URB Status. This field makes no sense for submissions, but is present 102- URB Status. This field makes no sense for submissions, but is present
103 to help scripts with parsing. In error case, it contains the error code. 103 to help scripts with parsing. In error case, it contains the error code.
104 In case of a setup packet, it contains a Setup Tag. If scripts read a number
105 in this field, the proceed to read Data Length. Otherwise, they read
106 the setup packet before reading the Data Length.
107- Setup packet, if present, consists of 5 words: one of each for bmRequestType,
108 bRequest, wValue, wIndex, wLength, as specified by the USB Specification 2.0.
109 These words are safe to decode if Setup Tag was 's'. Otherwise, the setup
110 packet was present, but not captured, and the fields contain filler.
104- Data Length. This is the actual length in the URB. 111- Data Length. This is the actual length in the URB.
105- Data tag. The usbmon may not always capture data, even if length is nonzero. 112- Data tag. The usbmon may not always capture data, even if length is nonzero.
106 Only if tag is '=', the data words are present. 113 Only if tag is '=', the data words are present.
@@ -125,25 +132,31 @@ class ParsedLine {
125 String data_str = st.nextToken(); 132 String data_str = st.nextToken();
126 int len = data_str.length() / 2; 133 int len = data_str.length() / 2;
127 int i; 134 int i;
135 int b; // byte is signed, apparently?! XXX
128 for (i = 0; i < len; i++) { 136 for (i = 0; i < len; i++) {
129 data[data_len] = Byte.parseByte( 137 // data[data_len] = Byte.parseByte(
130 data_str.substring(i*2, i*2 + 2), 138 // data_str.substring(i*2, i*2 + 2),
131 16); 139 // 16);
140 b = Integer.parseInt(
141 data_str.substring(i*2, i*2 + 2),
142 16);
143 if (b >= 128)
144 b *= -1;
145 data[data_len] = (byte) b;
132 data_len++; 146 data_len++;
133 } 147 }
134 } 148 }
135 } 149 }
136} 150}
137 151
138This format is obviously deficient. For example, the setup packet for control 152This format may be changed in the future.
139transfers is not delivered. This will change in the future.
140 153
141Examples: 154Examples:
142 155
143An input control transfer to get a port status: 156An input control transfer to get a port status.
144 157
145d74ff9a0 2640288196 S Ci:001:00 -115 4 < 158d5ea89a0 3575914555 S Ci:001:00 s a3 00 0000 0003 0004 4 <
146d74ff9a0 2640288202 C Ci:001:00 0 4 = 01010100 159d5ea89a0 3575914560 C Ci:001:00 0 4 = 01050000
147 160
148An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper 161An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
149to a storage device at address 5: 162to a storage device at address 5: