On 03/08/2016 01:48 PM, Ramesh Shanmugasundaram wrote: >> In fact you provided a CAN driver which is "CAN-FD-only". > > Yes. That's the status of current submission. > >> We did not had that before but there's a solution for this kind of setup. >> >> There is a similar case with CAN_CTRLMODE_FD_NON_ISO we had on the M_CAN >> driver which only provides non-ISO configuration for the supported IP core >> and _no_ option to _change_ this value: >> >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id >> =6cfda7fbebe8a4fd33ea5722fa0212f98f643c35 >> >> If you would do it similar in rcar_canfd.c with >> >> /* CAN_CTRLMODE_FD is fixed with R-Car CAN FD */ >> priv->can.ctrlmode = CAN_CTRLMODE_FD; >> >> and remove CAN_CTRLMODE_FD from the priv->can.ctrlmode_supported >> assignment then it should do the entire configuration process correctly >> for you. >> Including the proper tests for the two bitrates. >> (see open_candev() in linux/drivers/net/can/dev.c) >> >> Right? > > I did try this option earlier but there are two problems with this method. > > 1) Below configuration is not possible > > ip link set can0 up type can bitrate 1000000 dbitrate 1000000 fd on > > "fd on" -> This is not allowed because CAN_CTRLMODE_FD bit is not set in ctrlmode_supported. > > 2) If I ignore "fd on", my interface MTU stays as CAN_MTU only. If I have to change the MTU alone to CANFD_MTU using another netlink message, it again checks ctrlmode_supported where it would fail. I have the option of providing my own change_mtu function & ignore this check but two configuration messages are required for my driver alone :-(. > > Both these anomalies are addressed with the current check I have. Oh - you are right with complaining about this inconsistency. Can you check my RFC patch for Linux stable I just sent on the mailing list? http://marc.info/?l=linux-can&m=145745724917976&w=2 Many thanks, Oliver
