From zaitcev@redhat.com Sat Jun 25 14:33:47 2005 Date: Sat, 25 Jun 2005 14:32:59 -0700 From: Pete Zaitcev To: greg@kroah.com Cc: zaitcev@redhat.com Subject: USB: Patch to make usbmon to print control setup packets Message-Id: <20050625143259.5d9770fc.zaitcev@redhat.com> 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 Signed-off-by: Greg Kroah-Hartman --- Documentation/usb/usbmon.txt | 29 ++++++++++++++++++------- drivers/usb/mon/mon_text.c | 48 ++++++++++++++++++++++++++++++++++++++----- 2 files changed, 64 insertions(+), 13 deletions(-) --- gregkh-2.6.orig/Documentation/usb/usbmon.txt 2005-06-17 12:48:29.000000000 -0700 +++ gregkh-2.6/Documentation/usb/usbmon.txt 2005-06-28 13:50:08.000000000 -0700 @@ -101,6 +101,13 @@ 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 @@ 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: --- gregkh-2.6.orig/drivers/usb/mon/mon_text.c 2005-06-17 12:48:29.000000000 -0700 +++ gregkh-2.6/drivers/usb/mon/mon_text.c 2005-06-28 13:50:08.000000000 -0700 @@ -19,11 +19,16 @@ #define DATA_MAX 32 /* + * Defined by USB 2.0 clause 9.3, table 9.2. + */ +#define SETUP_MAX 8 + +/* * This limit exists to prevent OOMs when the user process stops reading. */ #define EVENT_MAX 25 -#define PRINTF_DFL 120 +#define PRINTF_DFL 130 struct mon_event_text { struct list_head e_link; @@ -33,7 +38,9 @@ unsigned int tstamp; int length; /* Depends on type: xfer length or act length */ int status; + char setup_flag; char data_flag; + unsigned char setup[SETUP_MAX]; unsigned char data[DATA_MAX]; }; @@ -64,6 +71,22 @@ * This is called with the whole mon_bus locked, so no additional lock. */ +static inline char mon_text_get_setup(struct mon_event_text *ep, + struct urb *urb, char ev_type) +{ + + if (!usb_pipecontrol(urb->pipe) || ev_type != 'S') + return '-'; + + if (urb->transfer_flags & URB_NO_SETUP_DMA_MAP) + return 'D'; + if (urb->setup_packet == NULL) + return 'Z'; /* '0' would be not as pretty. */ + + memcpy(ep->setup, urb->setup_packet, SETUP_MAX); + return 0; +} + static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, int len, char ev_type) { @@ -90,7 +113,6 @@ /* * Bulk is easy to shortcut reliably. - * XXX Control needs setup packet taken. * XXX Other pipe types need consideration. Currently, we overdo it * and collect garbage for them: better more than less. */ @@ -144,6 +166,7 @@ /* Collecting status makes debugging sense for submits, too */ ep->status = urb->status; + ep->setup_flag = mon_text_get_setup(ep, urb, ev_type); ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type); rp->nevents++; @@ -299,10 +322,25 @@ default: /* PIPE_BULK */ utype = 'B'; } cnt += snprintf(pbuf + cnt, limit - cnt, - "%lx %u %c %c%c:%03u:%02u %d %d", + "%lx %u %c %c%c:%03u:%02u", ep->id, ep->tstamp, ep->type, - utype, udir, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe), - ep->status, ep->length); + utype, udir, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe)); + + if (ep->setup_flag == 0) { /* Setup packet is present and captured */ + cnt += snprintf(pbuf + cnt, limit - cnt, + " s %02x %02x %04x %04x %04x", + ep->setup[0], + ep->setup[1], + (ep->setup[3] << 8) | ep->setup[2], + (ep->setup[5] << 8) | ep->setup[4], + (ep->setup[7] << 8) | ep->setup[6]); + } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ + cnt += snprintf(pbuf + cnt, limit - cnt, + " %c __ __ ____ ____ ____", ep->setup_flag); + } else { /* No setup for this kind of URB */ + cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->status); + } + cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->length); if ((data_len = ep->length) > 0) { if (ep->data_flag == 0) {