On 21.02.2024 15:14:02, Oliver Hartkopp wrote: > I have an old PCAN USB adapter (Classical CAN) which uses the pcan_usb > driver and wanted to set a 50kbit/s bitrate: > > ip link set can0 up txqueuelen 500 type can bitrate 50000 sjw 4 > > First it complained about the SJW having a higher value than some phase-seg > value which was 2. > > Error: sjw: 4 greater than phase-seg2: 2. > > I always thought the driver automatically adapts the SJW value to the > highest possible and SJW=4 could always be set. Did this change at a certain > point? Yes, that changed with b5a3d0864ee7 ("can: bittiming: can_sjw_check(): check that SJW is not longer than either Phase Buffer Segment") See discussion in https://lore.kernel.org/all/20220907103845.3929288-3-mkl@xxxxxxxxxxxxxx/ > Anyway, then I reduced the given SJW value and the ip command did not give > any error message. > > But finally there was not CAN traffic possible with my "always working > setup". > > I'm running 6.8.0-rc4-00433-g92a355464776 from Linus' tree. > > Reverting this patch fixed my issue. But what has the tdco calculation to do with non CAN-FD controllers? Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung Nürnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
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