On 09. 03. 19 15:40, Appana Durga Kedareswara Rao wrote: > Hi Andre, > > <Snip> >> >> On 3/9/19 3:07 PM, Appana Durga Kedareswara rao wrote: >>> While stress testing the CAN interface on xilinx axi can in loopback >>> mode getting message "write: no buffer space available" >>> Increasing device tx queue length resolved the above mentioned issue. >> >> No need to patch the kernel: >> >> $ ip link set <dev-name> txqueuelen 500 >> >> does the same thing. > > Thanks for the review... > Agree but it is not an out of box solution right?? > Do you have any idea for socket can devices why the tx queue length is 10 > whereas > for other network devices (ex: ethernet) it is 1000 ?? > > Regards, > Kedar.
There was already a patch for this in the past [1], together with a thorough analysis, but for some reason the discussion died out. Even if the defaults are not changed, it would be nice to at least see it mentioned in Documentation/networking/can.txt to save people some time while looking for the solution. Regards, Martin [1] http://socket-can.996257.n3.nabble.com/Solving-ENOBUFS-returned-by-write-td2886.html >> >>> >>> Signed-off-by: Appana Durga Kedareswara rao >>> <appana.durga....@xilinx.com> >>> --- >>> --> Network devices default tx_queue_len is 1000 but for socket >>> can device it is 10 any reason for it?? >>> >>> drivers/net/can/dev.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index >>> c05e4d5..32bd5be 100644 >>> --- a/drivers/net/can/dev.c >>> +++ b/drivers/net/can/dev.c >>> @@ -642,7 +642,7 @@ static void can_setup(struct net_device *dev) >>> dev->mtu = CAN_MTU; >>> dev->hard_header_len = 0; >>> dev->addr_len = 0; >>> - dev->tx_queue_len = 10; >>> + dev->tx_queue_len = 500; >>> >>> /* New-style flags. */ >>> dev->flags = IFF_NOARP; >>> >
