I'm running a program with two CAN channels (using TowerTech CAN Cape TT3201).
The two channels are can0 (500k) and can1 (125k). The can0 channels works perfectly but can1 runs a write:No buffer space available error.
I'm using ValueCAN3/VehicleSpy to check the messages.
This is before I run the program. can0 and can1 both seem to send, but only can0 shows up in VehicleSpy.
root@cantool:~# cansend can0 100#00
root@cantool:~# cansend can1 100#20
This is after I try running the program
root@cantool:~# cansend can1 100#20
write: No buffer space available
root@cantool:~# cansend can0 111#10
While my program is running : I get this error for all messages to be sent on can1
2016-11-02 15:36:03,052 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 12f83018 010 1 00
2016-11-02 15:36:03,131 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 0af81118 010 6 00 00 00 00 00 00
2016-11-02 15:36:03,148 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 12f81018 010 6 00 00 00 00 00 00
2016-11-02 15:36:03,174 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 0af87018 010 3 00 00 00
2016-11-02 15:36:03,220 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 12f89018 010 4 00 00 00 00
2016-11-02 15:36:03,352 - can.socketcan.native.tx - WARNING - Failed to send: 0.000000 12f83018 010 1 00
However sometimes the whole program works perfectly (if the module is rebooted or some random instances).
How do I fix this?
root@cantool:~# uname -r
4.1.15-ti-rt-r43
after doing some digging, I found this
root@cantool:-#ip -details link show can0
4:can0: <NOARP,UP,LOWER_UP, ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
link/can promiscuity 0
can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 100
bitrate 500000 sample-point 0.875
tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
c_can: tseg1 2..16 tseg2 1..8 sjw 1..4 brp 1..1024 brp-inc 1
clock 24000000
root@cantool:-#ip -details link show can1
5: can1: <NOARP,UP,LOWER_UP, ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
link/can promiscuity 0
can state STOPPED restart-ms 100
bitrate 125000 sample-point 0.875
tq 500 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
c_can: tseg1 2..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
clock 8000000
Turns out that can1 is STOPPED for some reason
however when I try:
ip link set can1 type can restart
RNETLINK answers: Invalid argument
After you enable the can0
interface with sudo ifconfig can0 up
, run:
sudo ifconfig can0 txqueuelen 1000
This will increase the number of frames allowed per kernel transmission queue for the queuing discipline. More info here
... sometimes the whole program works perfectly (if the module is rebooted or some random instances).
The reason why it works when you restart the SocketCAN interface, is that you might clear up just enough buffer space to make it work.