On Sat, 2016-08-20 at 14:14 +0200, Julio Guerra wrote:
> >> Another example:
> >>> 00 00 00 00 00 00 00 01
> >> ...
> >>> 01 00 00 00 00 00 00 00
> >> ...
> >>> 00 01 00 00 00 00 00 00
> >> ...
> >>> 00 00 01 00 00 00 00 00
> >> after a random number of times, while usbmon shows the usb payload
> >> "00 00 00 00 00 00 00 01".
> >
> > Hi, how many bytes does read() return?
> >
>
> Exactly 8 bytes, always. I set the tty in raw non-canonical mode with
> vmin = 8 and vtime = 0. I also tried with vmin = 1 and did the copy of
> exactly 8 bytes by looping in userspace, without any improvement.
>
> I wrote a small workaround for now that detects this problem (because I
> exactly know what the buffer is supposed to look like) to close() and
> re-open() the device. The next read buffer is then correct.
>
Please activate dynamic debugging for the tty and cdc_acm driver.
We need to know where the corruption happens.
Regards
Oliver
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