On Tue, 24 Jul 2007, Ron Gage wrote: > > Don't you remember what I told you a few days ago? The setup packet > > contents in the "down" report are unreliable. You need to look at an > > "up" report. > > > > Alan Stern > > > > > I remember it quite clearly. You told me to look at the "UP" packets > which I did.
No, I said to look at the "up" _reports_. "report" != "packet". > I then responded about how those "UP" packets looked like > responses from the device to the host (a clear example: the response to > the Get_Descriptor_From_Device request is in an UP packet. For IN transfers (from the device to the host), yes, the transfer data is displayed in the "up" report. For OUT transfers (host to device) the transfer data is displayed in the "down" report. For control transfers, both reports contain a section labelled "Setup packet" but the values in the "down" report are wrong. > In fact, by looking over the entire capture session of 2,324 packets, I > am seeing 9 packets so far that are UP packets and appear to be from > host to device. All 9 of these UP packets are at the beginning of the > capture. In fact, after sequence #19, there are no UP packets that > appear to originate from the host at all - but there are hundreds of > down packets that appear to. > > > As I said before, I'm getting confused. First, stop thinking of those reports are packets. They aren't. They aren't even URBs, since each URB corresponds to a pair of reports: one "down" and one "up". The URB numbers are clearly listed in the log. I downloaded your log file. It contains 1162 URBs (numbered 1 through 1162). Each URB has two reports (a report appears a single line in the unexpanded view), a "down" followed by an "up". What could be clearer than that? (Stop thinking about packets. The log doesn't list individual packets, and you wouldn't be interested in them if it did. A single control URB typically consists of 9 packets; some have more and some have fewer.) As for the direction of data transfers, it's easy to tell. Transfers from the host to the device are labelled "out" in the log. Transfers from the device to the hoset are labelled "in". So for example, URB #10 has two lines in the log. The first is labelled "10 in down" and the second is labelled "10 in up". If you expand the second you will see the data sent by the device together with the correct Setup packet contents. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
