[Libusb-devel] libusb 0.1 bulk read works/ and libusb 0.9 bulk_transfer (read) does not

[jeffp <jm...@ya...>]

It is me again. I have put in a good  bit of effort myself trying to figure
this out, and the one from my other post just now talking about ENOENT on 
libusb_submit_transfer, but have not been able to make any progress so I am
hoping someone out there may be able to help a bit with either or both of
these issues.

The  issue in this post is very puzzling to me.

I have a protocol analyzer and am watching the calls  when do a bulk
transfer (read)  from both 1libusb 0.1 and 1.0/0.9

Using the 0.1, the operation succeeds (I download about 65K of data to my
device)

Using 1.0, the operation times out after just a few OUT packets are sent to
the host.  the he device sends a NAK back after a few packets, the host then
PINGS the device, and the device NAKs the PINGs, until the bulk_transfer
timesout.

I am trying read the  same amount of data for each. 
 almost all of the code in both cases is the same, except for the changes
needed to port the code to 1.0.  

The perplexing thing is that when I look at the transactions on the bus, I
see exactly the same thing up for both 0.1, and 1.0 until the failure
occurs. Same packet types, packets, endpoint values, etc. Even transaction
durations and inter-transaction intervals are almost identical. But as
mentioned above, with 0.1, the OUT packets continue until all have been sent
from the host , but with 1.0, only a few OUT packets are sent to the host,
and then the device starts NAKing. I cannot figure out why the device all of
a sudden thinks it does not have any more data to send. Like I mention above
all the transactions at the start of  the process are identical and the OUT
packets start in both cases, and these packets are identical.
 
i would suspect the device, but it seems to work with 0.1, and 1.0 control
xfers.

can anyone think of why this could occur, or what I might look into to find
the issue ?

thank you again for all the help. i truly appreciate it.

jeff p
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