SK-AM62A-LP: Issue with Native EtherCAT Driver Installation on AM62A with IGH Stack

Hi Debashis, 

Debashis Mahanty said:

modprobe: ERROR: could not insert 'ec_ti_am65_cpsw_nuss': Device or resource busy
failed

When you check "lsmod" before running IgH Ethernet master on your AM62Ax platform, do you see the "ec_ti_am65_cpsw_nuss" module already loaded? 

I'm currently out of office and won't be able to look your issue closely until I'm back in office next week, there might be some delay in my responses on this thread.

-Daolin

Hi Daolin,

Yes, we saw the module(ec_master) is inserted but not used.

root@mitysom-am62ax:/# lsmod | grep ec
ec_master             299008  0
ecdh_generic           16384  1 bluetooth
ecc                    36864  1 ecdh_generic
display_connector      12288  0
drm_kms_helper        200704  4 drm_dma_helper,display_connector,tidss,ti_tfp410
drm                   643072  6 drm_kms_helper,drm_dma_helper,display_connector,tidss,ti_tfp410

Both interfaces are linked to the same bus address (8000000.ethernet), which I understand represents a single CPSW Ethernet controller.

To illustrate the architecture:
-------------------------

Initially, I attempted to unbind the CPSW driver and restart the EtherCAT master. However, the same error persisted.

Upon further investigation, I found that both Ethernet ports (eth0 and eth1) are controlled by the same Ethernet hardware block. The ethtool output confirms this:

root@mitysom-am62ax:/# ethtool -i eth0
driver: am65-cpsw-nuss
version: 6.6.58-g7a2fa4c23070-dirty
firmware-version:
expansion-rom-version:
bus-info: 8000000.ethernet
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: yes
root@mitysom-am62ax:/# ethtool -i eth1
driver: am65-cpsw-nuss
version: 6.6.58-g7a2fa4c23070-dirty
firmware-version:
expansion-rom-version:
bus-info: 8000000.ethernet
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: yes

Summary of My Understanding:
Both eth0 and eth1 are logical ports of the same CPSW Ethernet hardware block.
The native EtherCAT driver requires exclusive access to the Ethernet controller.
It appears I cannot assign one port for EtherCAT and another for regular Linux networking, as both are tied to the same controller.

Rectify me if I am wrong.

Regards,
Debashis

Hi Debashis, 

Debashis Mahanty said:

Yes, we saw the module(ec_master) is inserted but not used.

Just for clarification, what was your network setup/topology when you observed this issue? Were both ports (EtherCAT and non-EtherCAT port) connected to devices prior to running the EtherCAT master? How did you specify which port is used for EtherCAT in the IgH configuration?

Debashis Mahanty said:

It appears I cannot assign one port for EtherCAT and another for regular Linux networking, as both are tied to the same controller.

From a brief test that I did a while back with IgH native driver running on AM62x I remember not encountering an issue with this though I may not have tested with the non-EtherCAT port connected to another device.

I used the instructions in https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1409114/faq-how-do-i-build-the-native-igh-ethercat-stack-for-ti-microprocessors to setup IgH native driver. Did you use the steps in this FAQ? Specifically, there is a step to setup up the kernel so that the CPSW driver is not built into the kernel but rather built as a module.

-Daolin

Hi Daolin,

Daolin Qiu said:

How did you specify which port is used for EtherCAT in the IgH configuration?

we followed the igh doc and the path is /etc/sysconfig/ethercat.

All commands are same except this 

sudo sed -e '/^DEVICE_MODULES=/s/""/"ti_am65_cpsw_nuss"/' \
-e '/^MASTER0_DEVICE=/s/""/"ff:ff:ff:ff:ff:ff"/' \
-i /usr/local/etc/ethercat.conf

But i have written the same in this file as well.


When starting the EtherCAT service using: /etc/init.d/ethercat start
it shows that driver is already loaded.

root@mitysom-am62ax:/ethercat_master_native/ethercat/sncn_installer# /etc/init.d/ethercat start
Starting EtherCAT master 1.6.1 [ 3095.840544] EtherCAT: Master driver 1.6.1 1.6-alpha-176-gdb48d9b0
[ 3095.847682] EtherCAT: 1 master waiting for devices.
[ 3095.890494] Error: Driver 'am65-cpsw-nuss' is already registered, aborting...
modprobe: ERROR: could not insert 'ec_ti_am65_cpsw_nuss': Device or resource busy
failed

when i check the dmesg:

[ 3095.840544] EtherCAT: Master driver 1.6.1 1.6-alpha-176-gdb48d9b0
[ 3095.847682] EtherCAT: 1 master waiting for devices.
[ 3095.890494] Error: Driver 'am65-cpsw-nuss' is already registered, aborting...


Regards,
Debashis

Hi Debashis, 

Debashis Mahanty said:

sudo sed -e '/^DEVICE_MODULES=/s/""/"ti_am65_cpsw_nuss"/' \
-e '/^MASTER0_DEVICE=/s/""/"ff:ff:ff:ff:ff:ff"/' \
-i /usr/local/etc/ethercat.conf

Thanks for clarifying how you specified which ports should be used for EtherCAT in the IgH configuration.

Daolin Qiu said:

Just for clarification, what was your network setup/topology when you observed this issue? Were both ports (EtherCAT and non-EtherCAT port) connected to devices prior to running the EtherCAT master?

Can you confirm on these two questions?

Daolin Qiu said:

I used the instructions in https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1409114/faq-how-do-i-build-the-native-igh-ethercat-stack-for-ti-microprocessors to setup IgH native driver. Did you use the steps in this FAQ? Specifically, there is a step to setup up the kernel so that the CPSW driver is not built into the kernel but rather built as a module.

Can you try out the instructions in this FAQ if you haven't done so yet? This FAQ is a resource for people who want to try out IgH EtherCAT stack using CPSW ethernet native driver and is separate from the IgH documentation (though some steps may be sourced from the IgH documentation).

-Daolin

Hi Daolin,

Daolin Qiu said:

Can you confirm on these two questions?

Master Processor(Ethernet 1)------>Ti Sitara(EtherCAT master) ---------> Motor

This is our network topology but i have tried with out Master Processor as well we face the same issue as previous.

For your Information we have already build the kernel for our Processor to make docker work based on TI suggestion. So, I have checked this flag on .config file. It was enabled. 
CONFIG_TI_K3_AM65_CPSW_NUSS=y

This is our script to install ethercat which is almost same with some extra add-ons to make life easier. 



# Setup parameters
ETHERCAT_USER_GROUP="$(whoami)"
UDEV_RULES_FILE="/etc/udev/rules.d/99-EtherCAT.rules"
SCRIPT_DIR="$(cd "$( dirname "$0" )" && pwd)"
WORK_DIR="${SCRIPT_DIR}/.."
SYSCONFIG_DIR="/etc/sysconfig/"
ETHERCAT_SYSCONFIG="/etc/sysconfig/ethercat"
ETHERCAT_INSTALL_PREFIX="/opt/etherlab"
CONFIGURE_FLAGS="--enable-sii-assign --disable-8139too --enable-hrtimer --enable-cycles --enable-generic --disable-eoe"

do_configure() {
  cd ${WORK_DIR}

  echo -n "char* gitlog = \"" > master/gitlog.h && \
    git log | head -1 | awk '{printf "%s", substr($2,1,8)}' >> master/gitlog.h && \
    echo "\";" >> master/gitlog.h

  ./bootstrap
  ./configure ${CONFIGURE_FLAGS} --prefix=${ETHERCAT_INSTALL_PREFIX}

  if [[ -f "/etc/init.d/ethercat" ]]; then
    sudo /etc/init.d/ethercat stop
  elif [[ -f "${ETHERCAT_INSTALL_PREFIX}/etc/init.d/ethercat" ]]; then
    sudo ${ETHERCAT_INSTALL_PREFIX}/etc/init.d/ethercat stop
  fi
}

do_compile () {
  make clean
  make all modules
}

do_install () {
  sudo make modules_install install
  sudo ldconfig
  sudo depmod

  # Link the service
  if [[ -f "/etc/init.d/ethercat" ]]; then
    sudo rm /etc/init.d/ethercat
  fi
  sudo ln -s ${ETHERCAT_INSTALL_PREFIX}/etc/init.d/ethercat /etc/init.d/ethercat

  # Link the binary
  if [[ -f "/usr/bin/ethercat" ]]; then
    sudo rm /usr/bin/ethercat
  fi
  sudo ln -s ${ETHERCAT_INSTALL_PREFIX}/bin/ethercat /usr/bin/ethercat
}

do_setup_interfaces () {
  # Add udev rule
  sudo rm -rf ${UDEV_RULES_FILE}
  echo "KERNEL==\"EtherCAT[0-9]*\", MODE=\"0664\", GROUP=\"${ETHERCAT_USER_GROUP}\"" | sudo tee --append ${UDEV_RULES_FILE}

  # Link the sysconfig EtherCAT file
  if [[ -f "${ETHERCAT_SYSCONFIG}" ]]; then
    sudo rm ${ETHERCAT_SYSCONFIG}
  else
    sudo mkdir -p ${SYSCONFIG_DIR}
  fi
  sudo ln -s ${ETHERCAT_INSTALL_PREFIX}${ETHERCAT_SYSCONFIG} ${ETHERCAT_SYSCONFIG}

  # Add detected interfaces and delete old ones
  sudo sed -i --follow-symlinks '/MASTER[^0].*_DEVICE/d' ${ETHERCAT_SYSCONFIG}

  # Intel Up square 2
  # 2nd ethernet is used for this board
  if [[ -n $(lscpu | sed '13q;d' | grep "Intel(R) Pentium(R) CPU N4200 @ 1.10GHz") ]];then
    MAC=$(cat /sys/class/net/enp3s0/address)
  else
  # Standard laptop
    if [[ -n "${1}" ]];then
      # Use interface passed as parameter if it is passed
      iface="${1}"
      MAC=$(cat /sys/class/net/${iface}/address)
    else
      # Takes the first interface randomly if not passed
      interfaces=$(ip link show  | grep -oP "(^\d*: )\K(e[tn][a-z0-9]*)")
      iface=$(echo ${interfaces} | head -n1 | cut -d " " -f1)
      MAC=$(cat /sys/class/net/${iface}/address)
    fi
  fi
  sudo sed -i --follow-symlinks "s/MASTER0_DEVICE=\"\"/MASTER0_DEVICE=\"${MAC}\"/g" ${ETHERCAT_SYSCONFIG}
  sudo sed -i --follow-symlinks 's/DEVICE_MODULES=\"\"/DEVICE_MODULES=\"generic\"/g' ${ETHERCAT_SYSCONFIG}
}

do_start() {
  if [[ -f "/etc/init.d/ethercat" ]]; then
    sudo /etc/init.d/ethercat start
  elif [[ -f "${ETHERCAT_INSTALL_PREFIX}/etc/init.d/ethercat" ]]; then
    sudo ${ETHERCAT_INSTALL_PREFIX}/etc/init.d/ethercat start
  fi
}

do_configure
do_compile
do_install
do_setup_interfaces $1
do_start

echo "Done"

Regards,
Debashis

Hi,

This is my updated flag to install ethercat don't consider the above.
CONFIGURE_FLAGS="--enable-sii-assign --disable-8139too --enable-hrtimer --enable-cycles --disable-generic --disable-eoe --enable-am65cpsw"

Hi Debashis, 

Below is the result of what I see when I start EtherCAT when both ports of my AM62x EVM were connected, eth0 port to EtherCAT network and eth1 to a 1Gbps Ethernet switch. I used the steps specified in the FAQ. Perhaps you can try "ethercatctl start"?

Debashis Mahanty said:

Yes, we saw the module(ec_master) is inserted but not used.

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root@mitysom-am62ax:/# lsmod | grep ec

ec_master 299008 0

ecdh_generic 16384 1 bluetooth

ecc 36864 1 ecdh_generic

display_connector 12288 0

drm_kms_helper 200704 4 drm_dma_helper,display_connector,tidss,ti_tfp410

drm 643072 6 drm_kms_helper,drm_dma_helper,display_connector,tidss,ti_tfp410

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

root@mitysom-am62ax:/# lsmod | grep ec
ec_master             299008  0
ecdh_generic           16384  1 bluetooth
ecc                    36864  1 ecdh_generic
display_connector      12288  0
drm_kms_helper        200704  4 drm_dma_helper,display_connector,tidss,ti_tfp410
drm                   643072  6 drm_kms_helper,drm_dma_helper,display_connector,tidss,ti_tfp410

The fact that you see "ec_master" rather than "ec_ti_am65_cpsw_nuss" as the module seems to imply that you didn't fully setup the native driver since the native driver should be named "ec_ti_am65_cpsw_nuss" but you see the module as "ec_master" (this seems to me to be the generic IgH driver).

Debashis Mahanty said:

For your Information we have already build the kernel for our Processor to make docker work based on TI suggestion. So, I have checked this flag on .config file. It was enabled. 
CONFIG_TI_K3_AM65_CPSW_NUSS=y

This is our script to install ethercat which is almost same with some extra add-ons to make life easier. 

I understand that your steps may be similar to the FAQ steps but I still suggest trying to follow the steps in the FAQ step-by-step, at least as a sanity check, especially given that I don't currently see the same issue with starting EtherCAT master.

-Daolin