Re: [RESOLVED] Re: timeouts on USB ISP programmer

From: Tomek CEDRO <>
Date: Thu, 21 Apr 2022 18:34:13 UTC
On Thu, Apr 21, 2022 at 7:05 PM Axel Rau <> wrote:
> With the trace, recorded by Joerg Wunsch (author of avrdude),
> Hans found the implementation bug in the device.
> He wrote to Joerg:
> ====
> I see from the Ellisys .png's what is wrong. The device doesn't support
> resetting the data-toogle (CLEAR ENDPOINT HALT) which is a mandatory USB
> control endpoint command. So the USB stack tries a couple of times and then
> gives up and resets the device!
> The device is not class compliant! :-(
> Probably setting:
> sysctl hw.usb.no_cs_fail=1
> may help.
> ====
> Indeed with this setting the device works perfectly:
> (..)
> has been notified about the bug.
> Man thanks to all, who responded, especially Hans and Tomek,
> Axel

WOW! That was quite a journey! Thanks for the sysctl hint this may
come handy! :-)

I just wonder if this is the Diamex-only problem or all STK500v2
interfaces.. maybe they are just using public firmware on their own
hardware.. in that case all STK500v2 devices could be affected :-)

Hans is also my hero, I am rooting for the battle against some XHCI
controller on ARM hardware on the freebsd-usb list, man, patches are
already in the kernel :-) :-)

Have fun and take care! :-)