Messages lost on high CAN FD bit-rates

[mac-can]

Testcase TC12.6 failed: expected != received

TC12.6 - Read CAN FD messages from the receive queue and check for amount and order:

• 1Mbps (arbitration) and 8Mbps (data phase)
• 131072 CAN FD messages of size 64 bytes sent back to back

Assumption: It seems that the CAN FD capable PCAN USB devices send greater URBs than they report as endpoint packet size (512 byte. for pipe 3: input pipe for received CAN messages). The PCBUSB library provides a double buffer with size of 512 bytes (each). One buffer can hold up to 4 CAN FD message entries of 96 bytes but occasionally there is an incomplete 5th one in the packet. An incomplete entry could not be decoded, so this message get lost.

[mac-can]

Rootcause: With bulk transfers there can be more than one packet in an URB!

1. PCAN-USB (not CAN FD capable):
   Default packet size is 64 bytes, but up to 512 bytes are possible within one bulk transfer (needed packet by packet for decoding).
2. PCAN-USB FD and PCAN-USB Pro FD:
   Default packet size is 512 bytes, but up to 1024 bytes are possible within one bulk transfer (needed in one piece for decoding).

Solution: Will be fixed with version 0.11.2.

[mac-can]

Bug fix release v0.11.2 available. Issue can be closed.