RobertCNelson/ti-linux-kernel-dev

Beaglebone AI and I suspect all the BB don't work with etherCat

Closed this issue · 3 comments

lowkin18 commented

Hello,
I was unable to get the Simple Open EtherCAT Master software working on the BBAI with 4.14, 4.19 and 5.4. I brought this up with the guys in charge of the SOEM repository and they linked me to this potential issue.

https://patchwork.kernel.org/patch/10697191/

The CPSW ethernet hardware is padding the packets wrong, which is causing issue with some industrial automation protocols.
Such as my experience with a EtherCAT slave not responding to packets sent form the BBAI.

I was able to fix this by changing min packet size to 60 in cpsw.c when rebuilding the kernel

I hope this is the correct location to post this.

Cheers,

Chris

#EDIT
on further analysis looks like TI is aware of this and it needs to stay as is to work with VLAN properly.
I'll close this issue and just implement the work around for my use case.

RobertCNelson commented

@lowkin18 please keep us updated, we'd like to see ethercat working, but dont' have the hardware to verify it..

lowkin18 commented

@lowkin18 please keep us updated, we'd like to see ethercat working, but dont' have the hardware to verify it..

Hello Robert,

I was able to get it working by making a change to tx_packet_min=60 in cpsw.c locate at "ti-linux-kernel-dev/KERNEL/drivers/net/ethernet/ti/cpsw.c"

I am now trying to do it using the built module parameter that is in the 5.4 version

static int tx_packet_min = CPSW_MIN_PACKET_SIZE;
module_param(tx_packet_min,int,0444);
MODULE_PARM_DESC(tx_packet_min, "minimum tx packet size (bytes)");

I however am relatively new to embedded linux and don't really know the correct way to change a module parameter that is baked into the kernel. I will report back once I get it working through this module parameter way.

lowkin18 commented

I am struggling to find where I would setup the kernel cmdline to pass in the ti_cpsw.tx_packet_min=60
Is this a file that lives in ti-linux-kernel-dev or something I am supposed to pipe in from u-boot.

There are so many config files, in the deploy there is one but it seems that's just a generated output.