Three traces are now available:
http://www.eecs.umich.edu/~mcorner/linux_mydev.usb
http://www.eecs.umich.edu/~mcorner/win_mydev.usb
http://www.eecs.umich.edu/~mcorner/linux_camera.usb
I have included a summary of the first two traces below.
Also after further study this is what I have found: The camera doesn't
work for what appears to be a DIFFERENT reason. In that case the zero
length data packet is never sent after the set_address. We can deal with
this later. (BTW, there are several different Intel USB cameras. Some may
work) Right now let's focus on my_dev.
It seems that windows fails on the first round as well, but it tries again
and succeeds. Perhaps the stack should start over on the enumeration from
the beginning? Also windows sends most commands in sperate frames, rather
than using the same frame. This may be the cause of the NAKs. I realize
that we are probably within spec and the devices suck and windows
compensates. However, it looks like we will have to fix this or risk
being incompatible.
Here are the summaries.
I use 'show USB transactions' for clarity. Each time index is the closest
frame number. I haven't figured out all the triggering stuff yet.
linux_mydev.usb
260 RESET
490 Initial GET_DESCRIPTOR, ACK
Several IN commands followed by NAKs
Device sends DESCRIPTOR
host sends OUT.
492 SET_ADDRESS, ACK
HOST sends IN, several NAKs
Device sends 0 length data packet on addr 0 (this is required by
spec)
510 GET_DESCRIPTOR, no response or NAK (5*3 times)
win_mydev.usb
160 RESET
231 Initial GET_DESCRIPTOR, ACK
232 IN followed by device descriptor
234 host sends OUT
235 RESET (why?)
336 SET_ADDRESS, ack
337 HOST sends IN, gets 0 length data packet on addr0
351 GET_DESCRIPTOR, no response or NAK (3 times)
930 RESET
1071 Initial GET_DESCRIPTOR, ACK
1072 IN followed by device descriptor
1074 host sends OUT
1075 RESET (again, this strange reset)
1176 SET_ADRESS, ACK
1177 IN followed by 0 length data
1191 GET_DESCRIPTOR, ACKed!
proceeds normally from here....
----
Mark Douglas Corner
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