CMSIS-DAP V1 Issue on Linux

[BogdanTheGeek]

This is a continuation of #1825

The issue above was fixed by correct parsing of HID descriptors. This issue seems to be somewhere else as it emits no relevant logs.
I have tried to set the backend though the env, but it made no difference.

Bus 001 Device 048: ID 1209:d003 Generic RV003 CMSIS-DAP V1.3

> ./pyocd --version
0.40.1.dev6+g46941d56b
> time ./pyocd list -vvvvvvvv -p
0000345 D Project directory: /home/bogdan/Downloads [session]
0000348 D [Errno 13] Access denied (insufficient permissions) while trying to interrogate a USB device (VID=3434 PID=0323). This can probably be remedied with a udev rule. See <https://github.com/pyocd/pyOCD/tree/master/udev> for help. [pyusb_backend]
0000366 D [Errno 13] Access denied (insufficient permissions) while trying to interrogate a USB device (VID=046d PID=c332). This can probably be remedied with a udev rule. See <https://github.com/pyocd/pyOCD/tree/master/udev> for help. [pyusb_backend]
0000366 D [Errno 13] Access denied (insufficient permissions) while trying to interrogate a USB device (VID=3434 PID=0323). This can probably be remedied with a udev rule. See <https://github.com/pyocd/pyOCD/tree/master/udev> for help. [pyusb_v2_backend]
0000367 D [Errno 13] Access denied (insufficient permissions) while trying to interrogate a USB device (VID=046d PID=c332). This can probably be remedied with a udev rule. See <https://github.com/pyocd/pyOCD/tree/master/udev> for help. [pyusb_v2_backend]
0000368 D [Errno 13] Access denied (insufficient permissions) while trying to interrogate a USB device (VID=3434 PID=0323). This can probably be remedied with a udev rule. See <https://github.com/pyocd/pyOCD/tree/master/udev> for help. [pyusb_backend]
0007639 C index out of range [__main__]
./pyocd list -vvvvvvvv -p  0.61s user 0.14s system 9% cpu 7.774 total

^^^^ none of these logs are related to my device as you can see from the VID:PID

Ive attached the capture for the same command as above, but filtered for only this usb device
pyocd.pcap.zip

[mathias-arm]

Can you try to add -L '*=debug'?
(note: there might not be enough debug statements to help this problem)

[BogdanTheGeek]

Sorry, didn't get a change to look at this until now.

> lsusb
Bus 001 Device 054: ID 1209:d003 Generic RV003 CMSIS-DAP V1.3

> pyocd --version
0.42.0
> pyocd list -vvvvvvvv -p -L '*=debug'
0000157 D 'Libusb 1' found as /home/bogdan/Documents/minimal-py32/venv/lib64/python3.13/site-packages/libusb_package/libusb-1.0.so [libloader]
0000238 D [cmd:0] New _Command [dap_access_cmsis_dap]
0000242 D Detaching Kernel Driver of Interface 0 from USB device (VID=1209 PID=d003). [pyusb_backend]
0000248 D   USB OUT> (2) 00 fe [pyusb_backend]
0000249 D   USB RD < (0)  [pyusb_backend]
0000249 C index out of range [__main__]

AFAIK, DAP Packets are always at least 64bytes, so i'm not sure what that usb out is doing here.

Here are some dmesg logs for completleness:

[4560275.724838] usb 1-1.1.2.1.2: new low-speed USB device number 64 using xhci-hcd
[4560275.815972] usb 1-1.1.2.1.2: New USB device found, idVendor=1209, idProduct=d003, bcdDevice= 1.10
[4560275.815975] usb 1-1.1.2.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[4560275.815976] usb 1-1.1.2.1.2: Product: RV003 CMSIS-DAP V1.3
[4560275.815977] usb 1-1.1.2.1.2: Manufacturer: BogdanTheGeek
[4560275.815977] usb 1-1.1.2.1.2: SerialNumber: 1234
[4560275.828855] input: CNLohr RV003 CMSIS-DAP V1.3 as /devices/platform/soc/702280000.usb/xhci-hcd.3.auto/usb1/1-1/1-1.1/1-1.1.2/1-1.1.2.1/1-1.1.2.1.2/1-1.1.2.1.2:1.0/0003:1209:D003.0044/input/input42
[4560275.828929] hid-generic 0003:1209:D003.0044: input,hidraw9: USB HID v1.10 Device [BogdanTheGeek RV003 CMSIS-DAP V1.3] on usb-xhci-hcd.3.auto-1.1.2.1.2/input0

[BogdanTheGeek]

@DavidLesnjak Anything else I can do to aid troubleshooting this? Like I said before, I am happy to send a programmer anywhere in the world really.

[BogdanTheGeek]

Any updates?

[DavidLesnjak]

Sorry for the late response. We have been tied up with higher-priority items.

We took a closer look at this on Linux, where pyOCD uses the pyusb backend.

Our current theory is that this is related to how transfer size is handled for this low-speed CMSIS-DAP v1 probe. The device appears to use 8-byte USB packets, while the actual HID report size may be larger. The proper fix here would be to obtain the actual report size from the device’s HID report descriptor and use that for reads and writes.

Could you please confirm these two points for your probe?

• Is the HID OUT report size actually 64 bytes?
• Is host-to-device traffic using a real interrupt OUT endpoint?

That would help confirm whether this is indeed the issue.

We do plan to address this, but I do not want to promise a near-term timeline at this point.

Thanks again for all the investigation and for offering hardware to help with debugging.

[BogdanTheGeek]

@DavidLesnjak
Understandable.
The HID report size is 64 bytes :https://github.com/BogdanTheGeek/ch32v003-daplink/blob/e9d91e5073fe09ed614ce851ebe53416714ab6f3/firmware/usb_config.h#L48
The traffic is using interrupt out.