(USB) Win sends request for unknown descriptor when trying to enumerate my CDC class device

V

vishnu

I am programming the firmware for Communication Device Class -device,
(to emulate a rs232 connection). When it's in the enumerating process,
windows send a GET_DESCRIPTOR request, with 0x0600 in the wValue field
- which is (as far as i can tell) a reserved request.

I am looking at other software that's supposed to do the same job, and
they do not support this request - so there's a good chance something
else is wrong with my driver.

Windows asks for this:
GET_DESCRIPTOR: STRING_DESCRIPTOR: LANG_ID
GET_DESCRIPTOR: STRING_DESCRIPTOR: SERIL_NB
GET_DESCRIPTOR: CONFIGURATION_DESCRIPTOR

then...
GET_DESCRIPTOR: RESERVED_DESCRIPTOR_TYPE (0x0600)

and I don't know what to do.. :-(
I have compared my configuration descriptor to one i found in a the
source for a similar project, and it looks good. The enumeration
continues and ends up in STATUS_NOT_SUPPORTED. It may be that the
request I'm referring to isn't important ant that theres some other
reason for the failure, but I haven't got enough experience with usb
to spot it yet. Another thing I find strange is that windows never
(unless i'm blid) asks for my DEVICE_DESCRIPTOR. weird.

Any help would be greatly appreciated!


I used USBTrace (< 30s installation) to dump the enumeration process,
i can post/send the trance in either USBTrace or html format to anyone
who is willing to look at it. (sources as well)
http://www.sysnucleus.com/USBTrace_Build_25_270207_Installer.exe
Great tool btw!

- I'll actually post it online somewhere when i get home, my proxy at
work wont let me do anything ;)
 
W

Walter Roberson

I am programming the firmware for Communication Device Class -device,
(to emulate a rs232 connection). When it's in the enumerating process,
windows send a GET_DESCRIPTOR request, with 0x0600 in the wValue field
- which is (as far as i can tell) a reserved request.

I can't seem to find even a little crumb of your question that is C
related. I would suggest that you should be asking in a Windows
programming newsgroup. (I would suggest that when you repost, you
make it clearer what assistance you were hoping for from other
people. You have stated that certain things have happened to you,
but I couldn't find a question buried in there.)
 

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