Re: Failed control transfer

From: Hans Petter Selasky <hps_at_selasky.org>
Date: Tue, 11 Oct 2022 11:42:46 UTC
On 10/11/22 13:31, Hans Petter Selasky wrote:
> On 10/11/22 13:13, Daniel O'Connor wrote:
>>
>>
>>> On 11 Oct 2022, at 21:30, Hans Petter Selasky <hps@selasky.org> wrote:
>>>
>>> On 10/11/22 12:05, Daniel O'Connor wrote:
>>>> In [6]: d.ctrl_transfer(0xc0, 176, 0x42, 0, 256, 1000)
>>>
>>> 255 and not 256 bytes!
>>
>> Same result :(
>>
>> -- 
>> Daniel O'Connor
>> "The nice thing about standards is that there
>> are so many of them to choose from."
>> -- Andrew Tanenbaum
>>
> 
> What does "usbdump -i usbusX -f Y -s 65536 -vvv" say?
> 

Maybe you should trace using usbdump from the start of attachment.

Maybe some USB request gets the device into a bad state and it starts 
returning STALL for all new requests!

The STALL message comes straight from the USB device!

--HPS