hlcand: ioctl TIOCSETD: Invalid argument

Ciusss89 commented 4 years ago

[347925.671075] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[347925.671107] ch341 3-1.2:1.0: device disconnected
[347927.639172] usb 3-1.2: new full-speed USB device number 101 using xhci_hcd
[347927.717373] usb 3-1.2: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.63
[347927.717376] usb 3-1.2: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[347927.717377] usb 3-1.2: Product: USB2.0-Serial
[347927.724224] ch341 3-1.2:1.0: ch341-uart converter detected
[347927.724763] usb 3-1.2: ch341-uart converter now attached to ttyUSB0
[347933.762689] kauditd_printk_skb: 8 callbacks suppressed

sudo hlcand -m 2 -s 500000 /dev/ttyUSB0 -F
[6] starting on TTY device /dev/ttyUSB0
ioctl TIOCSETD: Invalid argument

alexmohr commented 4 years ago

Thats an actual show stopper for this implementation. The line discipline is checked at multiple parts of the ioctl call chain and must be a valid kernel value. I haven't checked before.

Options now are:

Using another line discpline and hope no other process in the system uses it at this point (not very clean and error prone)
Implementing the kernel module in a different way by implementing a can driver. For this we have to make sure that the serial interface will still be loaded (probably the best way)
Implementing the line discipline in the kernel (probably will be rejected)

I'll probably look into the 2nd option because I think it is the most promising. Probably it will be necessary the read the mapping between device ID and name of the can device from a configuration.

alexmohr commented 4 years ago

Fixed in current implementation

alexmohr / usb-can

hlcand: ioctl TIOCSETD: Invalid argument #9