"No suitable bit timings found" error on gs_usb with high f_clock

[firtel-t]

I have an MKS CANable V2.0 with candleLight firmware installed.
I noticed that bit timing calculation for gs_usb was fixed in PR #1748.
However, when I try to set the bitrate to 250 kbps or lower, I always get the following error:

ValueError: No suitable bit timings found.

Interestingly, Cangaroo seems to work fine with 250 kbps on the same device, so I believe the hardware itself supports this bitrate.

I also tried calculating bit timings using the Bit Timing API example in the documentation, but I couldn't find any valid timing when setting f_clock=170MHz and bitrate under 400 kbps — the loop just outputs nothing.

Is there any solution or workaround to make it work at 250 kbps with gs_usb backend?

Environment:
OS: Windows 10
Python: 3.10.11
python-can: 4.5.0 (installed via pip)

[zariiii9003]

It does not find any bit imings because the bitrate prescaler would be outside the normal range (1 to 32):

BR: 250_000 bit/s, SP: 70.00%, BRP: 34, TSEG1: 13, TSEG2: 6, SJW: 4, BTR: E15Ch, CLK: 170MHz
BR: 250_000 bit/s, SP: 70.59%, BRP: 40, TSEG1: 11, TSEG2: 5, SJW: 4, BTR: E74Ah, CLK: 170MHz

Is there a way to reduce the can clock frequency on your device? 170Mhz seems unusually high for classic CAN.

[firtel-t]

Thank you for your support.
I was previously using the candleLight firmware from CANanable.io, but I found another version from this pull request.
This firmware supports STM32G431 and seems to use 80MHz for CAN.
I built and installed it on my MSK CANable2.0, and now it works perfectly.