3.6.3.3. PRU_ICSSG Ethernet¶
3.6.3.3.1. Introduction¶
Driver is developed complying to Linux Driver model and implements netdev and NAPI APIs along with other basic driver functions. Driver supports multiple instances of ICSSG each of which has two slices. Each slice consists of a pair of Programmable Real-Time Units (PRUs), Auxillary Programmable Real-time Units (RTUs) and TX Programmable Real-Time Units (TX_PRUS). So each ICSSG instance supports two Ethernet interfaces i.e. one per slice.
One of the key difference in the driver implementation compared to PRU-ICSS driver is the use of UDMA driver interface and ring accelerator driver available on Keystone III SoC to send/receive frames between ARM Host processor and PRU_ICSSG. This allows for efficient moving of data and is more efficient than the shared memory transport used in PRU-ICSS.
3.6.3.3.2. Supported platforms¶
SoC |
Number of external ports |
|---|---|
AM65X |
3 x ICSSG, 6 Ports max |
AM64X |
2 x ICSSG, 4 Ports max |
Boards Supported
The AM65x Evaluation Module provides a platform to quickly start evaluation of Sitara™ Arm® Cortex®-A53 AM65x Processors (AM6548, AM6546, AM6528, AM6527, AM6526) and accelerate development for HMI, networking, patient monitoring, and other industrial applications. It is a development platform based on the quad core Cortex-A53, dual Cortex-R5F processor that is integrated with ample connectivity such as PCIe, USB 3.0/2.0, Gigabit Ethernet, PRU_ICSSG Ethernet, etc.
On this platform one CPSW Ethernet port and two ICSSG2 Ethernet ports are available for use.
AM65x industrial development kit (IDK)
The AM65x Industrial Development Kit (IDK) is a development platform for evaluating the industrial communication and control capabilities of Sitara AM65x processors for applications in factory automation, drives, robotics, grid infrastructure, and more. AM65x processors include three PRU_ICSSG (Programmable Real-time Unit for Industrial Communications) sub-systems which can be used for gigabit industrial Ethernet protocols such as Profinet, EtherCAT, Ethernet/IP, and others.
On this platform one CPSW Ethernet port and two ICSSG2 Ethernet ports are available on the baseboard and 4 Ethernet ports, 2 each of ICSSG0 and ICSSG1 are available on the IDK application module.
3.6.3.3.3. Features supported¶
1G/100M/10M Full-Duplex Ethernet ports
100M/10M Half-Duplex Ethernet ports
RGMII mode with TX delay (configured in DTS). RX delay is not supported and has to be provided by PHY.
MII mode
Multiple TX queues (upto 4), single RX queue.
PTP Ordinary clock
PPS Out
Promiscuous mode
Different MII modes for Real-Time Ethernet ports (MII_G_RT1 and MII_G_RT2) on different PRU_ICSSG instances. For example, MII on a PRU_ICSSG1 port, and RGMII on a PRU_ICSSG2 port, is supported.
IRQ Coalescing also known as interrupt pacing.
Multi-cast HW filtering
XDP Native Mode and XDP Generic Mode
Cut Through forwarding
PHY Interrupt mode for ICSSG2
Features not supported
VLAN HW filtering
All-multi mode is always enabled
Different MII modes for Real-Time Ethernet ports (MII_G_RT1 and MII_G_RT2) on a single PRU_ICSSG instance. For example, MII_G_RT1=MII and MII_G_RT2=RGMII.
XDP with Zero-copy mode
Limitations
Both MIIx ports have to be enabled in DT even if one of them is not used (no Ethernet PHY wired) for proper PRU_ICSSG Ethernet driver work. Use fixed-link for unused port as workaround.
3.6.3.3.4. Driver Configuration¶
The TI Processor SDK has ICSSG driver enabled by default on supported platforms. In case of custom builds, please ensure following configs are enabled.
CONFIG_TI_PRUSS
CONFIG_REMOTEPROC
CONFIG_PRU_REMOTEPROC
CONFIG_TI_PRUSS_INTC
CONFIG_TI_DAVINCI_MDIO
CONFIG_TI_ICSS_IEP
CONFIG_TI_ICSSG_PRUETH
Module Build
Module build for the ICSSG driver is supported. To do this, use option ‘m’ for above configs, where applicable.
3.6.3.3.5. Device tree bindings¶
The DT bindings description can be found at:
3.6.3.3.6. User guide¶
3.6.3.3.6.1. Bringing Up interface¶
The network interface can be configured automatically depending on root file system or configured manually. Manual configuration:
ip addr add 192.168.1.1/24 dev eth1
ip link set dev eth1 up
< or >
ifconfig eth1 <ip> netmask <mask> up
3.6.3.3.6.2. Get information (ethtool)¶
3.6.3.3.6.2.1. Get driver information¶
The interface can be identified by using ethtool -i|--driver DEVNAME command.
It also provides some information about supported features.
~# ethtool -i eth1
driver: icssg-prueth
version:
firmware-version:
expansion-rom-version:
bus-info: pruss2_eth
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no
3.6.3.3.6.2.2. Display standard information about device/link¶
Run ethtool DEVNAME command without parameters.
~# ethtool eth1
Settings for eth1:
Supported ports: [ TP MII ]
Supported link modes: 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Link partner advertised pause frame use: Symmetric Receive-only
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Current message level: 0x00007fff (32767)
drv probe link timer ifdown ifup rx_err tx_err tx_queued intr tx_done rx_status pktdata hw wol
Link detected: yes
3.6.3.3.6.2.3. Display time stamping capabilities¶
The interface time stamping capabilities can be retrieved by using ethtool -T|--show-time-stamping DEVNAME command.
ethtool -T eth2
Time stamping parameters for eth2:
Capabilities:
hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE)
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 2
Hardware Transmit Timestamp Modes:
off (HWTSTAMP_TX_OFF)
on (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
none (HWTSTAMP_FILTER_NONE)
all (HWTSTAMP_FILTER_ALL)
3.6.3.3.6.2.4. Show permanent hardware address¶
The interface permanent hardware address can be retrieved by using ethtool -P|--show-permaddr DEVNAME command.
~# ethtool -P eth1
Permanent address: 70:ff:76:1d:5c:64
3.6.3.3.6.2.5. Query Channels information¶
The interface DMA Channels information can be retrieved by using ethtool-l|--show-channels DEVNAME command.
# ethtool -l eth1
Channel parameters for eth1:
Pre-set maximums:
RX: 1
TX: 4
Other: 0
Combined: 0
Current hardware settings:
RX: 1
TX: 1
Other: 0
Combined: 0
3.6.3.3.6.2.6. Show adapter statistics¶
The interface statistics can be retrieved by using ethtool -S|--statistics DEVNAME command.
It displays statistic for the ethernet port.
~# ethtool -S eth1
NIC statistics:
rx_good_frames: 1757
rx_broadcast_frames: 151
rx_multicast_frames: 585
rx_crc_error_frames: 0
rx_mii_error_frames: 0
rx_odd_nibble_frames: 0
rx_frame_max_size: 4972000
rx_max_size_error_frames: 0
rx_frame_min_size: 159104
rx_min_size_error_frames: 0
rx_overrun_frames: 0
rx_class0_hits: 1757
rx_class1_hits: 0
rx_class2_hits: 0
rx_class3_hits: 0
rx_class4_hits: 0
rx_class5_hits: 0
rx_class6_hits: 0
rx_class7_hits: 0
rx_class8_hits: 1757
rx_class9_hits: 1757
rx_class10_hits: 0
rx_class11_hits: 0
rx_class12_hits: 0
rx_class13_hits: 0
rx_class14_hits: 0
rx_class15_hits: 0
rx_smd_frags: 0
rx_bucket1_size: 159104
rx_bucket2_size: 318208
rx_bucket3_size: 636416
rx_bucket4_size: 1272832
rx_64B_frames: 1053
rx_bucket1_frames: 1053
rx_bucket2_frames: 366
rx_bucket3_frames: 88
rx_bucket4_frames: 250
rx_bucket5_frames: 0
rx_total_bytes: 203502
rx_tx_total_bytes: 1555610607
tx_good_frames: 1022405
tx_broadcast_frames: 2
tx_multicast_frames: 57
tx_odd_nibble_frames: 0
tx_underflow_errors: 0
tx_frame_max_size: 4972000
tx_max_size_error_frames: 0
tx_frame_min_size: 159104
tx_min_size_error_frames: 0
tx_bucket1_size: 159104
tx_bucket2_size: 318208
tx_bucket3_size: 636416
tx_bucket4_size: 1272832
tx_64B_frames: 0
tx_bucket1_frames: 0
tx_bucket2_frames: 3044
tx_bucket3_frames: 14
tx_bucket4_frames: 339
tx_bucket5_frames: 196605
tx_total_bytes: 1555407105
iet_bad_frag_slice0: 0
iet_bad_frag_slice1: 0
iet_asm_err_slice0: 0
iet_asm_err_slice1: 0
iet_tx_frag_slice0: 0
iet_tx_frag_slice1: 0
iet_asm_ok_slice0: 0
iet_asm_ok_slice1: 0
iet_rx_frag_slice0: 0
iet_rx_frag_slice1: 0
3.6.3.3.6.2.7. Show EEE settings¶
The interface EEE settings can be retrieved by using ethtool --show-eee DEVNAME command.
ethtool --show-eee eth1
EEE Settings for eth1:
EEE status: disabled
Tx LPI: disabled
Supported EEE link modes: 100baseT/Full
1000baseT/Full
Advertised EEE link modes: Not reported
Link partner advertised EEE link modes: 100baseT/Full
1000baseT/Full
3.6.3.3.6.3. VLAN Config¶
VLAN can be added/deleted using ip or vconfig utility.
VLAN Add
ip link add link eth1 name eth1.5 type vlan id 5
< or >
vconfig add eth1 5
VLAN del
ip link del eth1.5
< or >
vconfig rem eth1 5
VLAN IP assigning
IP address can be assigned to the VLAN interface either via udhcpc
when a VLAN aware dhcp server is present or via static ip assigning
using ip or ifconfig.
Once VLAN is added, it will create a new entry in Ethernet interfaces like eth1.5, below is an example how it check the vlan interface
ip addr add 10.0.0.5/24 dev eth1.5
< or >
ifconfig eth1.5 10.0.0.5
....
~# ifconfig eth1.5
eth1.5 Link encap:Ethernet HWaddr 70:FF:76:1D:5C:64
inet addr:10.0.0.5 Bcast:10.255.255.255 Mask:255.0.0.0
inet6 addr: fe80::72ff:76ff:fe1d:5c64/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:45 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:7590 (7.4 KiB)
VLAN Packet Send/Receive
To Send or receive packets with the VLAN tag, bind the socket to the proper Ethernet interface shown above and can send/receive via that socket-fd.
3.6.3.3.6.4. Interrupt pacing¶
The Interrupt pacing (IRQ coalescing) based on hrtimers for RX / TX data path separately can be enabled by ethtool commands (min value is 20us):
ethtool -C ethX rx-usecs N # Enable RX coalescing
ethtool -C ethX tx-usecs N # Enable TX coalescing for TX0 by default.
ethtool -Q ethX queue_mask 1 --coalesce tx-usecs 100 # Enable coalescing for TX0
ethtool -Q ethX queue_mask 2 --coalesce tx-usecs 100 # Enable coalescing for TX1
ethtool -Q ethX queue_mask 3 --coalesce tx-usecs 100 --coalesce tx-usecs 100 # Enable coalescing for both TX0 and TX1
The Interrupt pacing (IRQ coalescing) configuration can be retrieved by commands:
ethtool -c ethX # Show RX coalescing and TX coalescing for TX0
ethtool -Q ethX queue_mask 1 --show-coalesce # Show coalescing configuration for TX0
ethtool -Q ethX queue_mask 2 --show-coalesce # Show coalescing configuration for TX1
ethtool -Q ethX queue_mask 3 --show-coalesce # Show coalescing configuration for both TX0 and TX1
3.6.3.3.6.5. Multicast Add/Delete¶
Multicast MAC address can be added/deleted using ip maddr commands or Linux socket ioctl SIOCADDMULTI/SIOCDELMULTI.
Show muliticast address
~# ip maddr show eth1
3: eth1
link 33:33:00:00:00:01 users 2
link 01:00:5e:00:00:01 users 2
link 01:00:5e:00:00:fb users 2
link 33:33:ff:1d:5c:64 users 2
link 01:00:5e:00:00:fc users 2
link 33:33:00:01:00:03 users 2
link 33:33:00:00:00:fb users 2
link 01:80:c2:00:00:21 users 2
inet 224.0.0.252
inet 224.0.0.251
inet 224.0.0.1
inet6 ff02::fb
inet6 ff02::1:3
inet6 ff02::1:ff1d:5c64
inet6 ff02::1
inet6 ff01::1
Add muliticast address
~# ip maddr add 01:00:5e:00:00:05 dev eth1
~# ip maddr show dev eth1
3: eth1
link 33:33:00:00:00:01 users 2
link 01:00:5e:00:00:01 users 2
link 01:00:5e:00:00:fb users 2
link 33:33:ff:1d:5c:64 users 2
link 01:00:5e:00:00:fc users 2
link 33:33:00:01:00:03 users 2
link 33:33:00:00:00:fb users 2
link 01:80:c2:00:00:21 users 2
link 01:00:5e:00:00:05 static
inet 224.0.0.252
inet 224.0.0.251
inet 224.0.0.1
inet6 ff02::fb
inet6 ff02::1:3
inet6 ff02::1:ff1d:5c64
inet6 ff02::1
inet6 ff01::1
Delete muliticast address
# ip maddr del 01:00:5e:00:00:05 dev eth1
3.6.3.3.6.6. Promiscous Mode¶
By default promiscous mode is disabled. It can be enabled by using the below command.
Please note running a tool like tcpdump will itself enable promiscous mode.
ip link set eth0 promisc on
3.6.3.3.6.7. Configure interface (ethtool)¶
3.6.3.3.6.7.1. Change generic options¶
The interface generic options can be configured by using ethtool -s|--change DEVNAME command.
The main purpose of this command is to configure physical link settings (PHY) like speed, duplex, auto-negotiation.
Below commands will be redirected to the phy driver:
# ethtool -s <dev>
[ speed %d ]
[ duplex half|full ]
[ autoneg on|off ]
[ wol p|u|m|b|a|g|s|d... ]
[ sopass %x:%x:%x:%x:%x:%x ]
Note
ICSSG Ethernet driver does not perform any kind of WOL specific actions or configurations.
Below is an example of forcing link speed to 100M and duplexity to full:
# ethtool -s eth1 duplex full speed 100
[ 74.768324] icssg-prueth pruss2_eth eth1: Link is Down
[ 78.592924] icssg-prueth pruss2_eth eth1: Link is Up - 100Mbps/Full - flow control off
3.6.3.3.6.7.2. Restart N-WAY (PHY) negotiation¶
The interface PHY auto-negotiation can be restarted by using ethtool -r|--negotiate DEVNAME command.
# ethtool -r eth1
[ 273.151655] icssg-prueth pruss2_eth eth1: Link is Down
[ 276.225423] icssg-prueth pruss2_eth eth1: Link is Up - 1Gbps/Full - flow control off
3.6.3.3.6.7.3. Set Channels parameters¶
The interface DMA channels parameters can be set by using ethtool -L\|--set-channels DEVNAME command.
It allows to control number of TX channels driver is allowed to work with at DMA level. The maximum number of TX channels is 4.
Supported options [ tx N ]:
# ethtool -L eth1 tx 4
3.6.3.3.6.8. PTP Ordinary Clock¶
The PRU Ethernet & IEP drivers implement the Linux PTP hardware clock subsystem APIs, the PRU-ICSS PTP clock can therefore be adjusted by using those standard APIs. See PTP hardware clock infrastructure for Linux for more details.
The IEP0 is used by PRU Ethernet driver and Firmware PTP hardware clock and shared between PRU Ethernet ports. The IEP1 is used for Firmware purposes.
The PTP Ordinary Clock (OC) implementation is provided by the linuxptp application.
ptp4l -f oc.cfg
oc.cfg is a ptp4l configuration file.
Example oc.cfg for OC,
[global]
tx_timestamp_timeout 10
logMinPdelayReqInterval -3
logSyncInterval -3
twoStepFlag 1
summary_interval 0
[eth1]
delay_mechanism P2P
network_transport L2
where eth1 is the intended PRU-ICSSG Ethernet port over which the OC functionality is provided.
See The Linux PTP Project for more details about linuxptp in general and ptp4l(8) - Linux man page about ptp4l configurations in particular.
Here is a sample screen display of ptp4l for PRU-ICSS Ethernet port as PTP/OC in slave mode:
# ptp4l -f oc.cfg -s -m
ptp4l[1255.613]: selected /dev/ptp2 as PTP clock
ptp4l[1255.664]: port 1: INITIALIZING to LISTENING on INITIALIZE
ptp4l[1255.665]: port 0: INITIALIZING to LISTENING on INITIALIZE
ptp4l[1255.665]: port 1: link up
ptp4l[1263.081]: selected best master clock 70ff76.fffe.1d5c64
ptp4l[1269.343]: selected best master clock 70ff76.fffe.1d5c64
ptp4l[1271.367]: port 1: new foreign master d494a1.fffe.8c36e9-1
ptp4l[1275.368]: selected best master clock d494a1.fffe.8c36e9
ptp4l[1275.368]: port 1: LISTENING to UNCALIBRATED on RS_SLAVE
ptp4l[1275.754]: port 1: UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED
ptp4l[1276.381]: rms 789386424832367360 max 1578772849664738816 freq -60377 +/- 22862 delay 229 +/- 6
ptp4l[1277.385]: rms 473 max 729 freq -67059 +/- 642 delay 251 +/- 4
ptp4l[1278.389]: rms 792 max 830 freq -65620 +/- 211 delay 253 +/- 0
ptp4l[1279.393]: rms 504 max 667 freq -65335 +/- 17 delay 255 +/- 1
ptp4l[1280.397]: rms 166 max 271 freq -65484 +/- 59 delay 251 +/- 2
ptp4l[1281.401]: rms 26 max 42 freq -65649 +/- 34 delay 249 +/- 1
ptp4l[1282.405]: rms 43 max 50 freq -65727 +/- 10 delay 253 +/- 3
ptp4l[1283.409]: rms 26 max 39 freq -65739 +/- 6 delay 256 +/- 1
ptp4l[1284.412]: rms 5 max 7 freq -65725 +/- 3 delay 253 +/- 1
ptp4l[1285.416]: rms 5 max 7 freq -65717 +/- 6 delay 252 +/- 1
ptp4l[1286.420]: rms 11 max 14 freq -65698 +/- 6 delay 252 +/- 1
ptp4l[1287.424]: rms 8 max 12 freq -65693 +/- 5 delay 254 +/- 1
ptp4l[1288.427]: rms 7 max 12 freq -65687 +/- 4 delay 251 +/- 2
ptp4l[1289.430]: rms 4 max 8 freq -65686 +/- 3 delay 249 +/- 1
ptp4l[1290.434]: rms 5 max 8 freq -65693 +/- 7 delay 249 +/- 1
ptp4l[1291.438]: rms 4 max 9 freq -65696 +/- 5 delay 251 +/- 1
ptp4l[1292.441]: rms 7 max 9 freq -65682 +/- 5 delay 253 +/- 0
ptp4l[1293.445]: rms 11 max 14 freq -65667 +/- 4 delay 252 +/- 0
ptp4l[1294.448]: rms 8 max 14 freq -65662 +/- 5 delay 254 +/- 1
ptp4l[1295.452]: rms 6 max 8 freq -65659 +/- 5 delay 254 +/- 2
ptp4l[1296.456]: rms 3 max 7 freq -65657 +/- 2 delay 251 +/- 0
ptp4l[1297.459]: rms 4 max 5 freq -65661 +/- 6 delay 256 +/- 2
...
3.6.3.3.6.8.1. PPS Pulse Per Second support¶
PPS hardware pin is available only on the IDK application card i.e. ICSSG0 port 0 and ICSSG1 port 1. They are available at LEDs LD2 and LD5 respectively.
PPS can be tested using testptp.c tool.
To find out the PTP device number i.e. PTP Hardware Clock, use ethtool -T DEVNAME
Note
For PPS to work, the firmware needs to be running so the ICSSG network interface must be brought up.
To turn on PPS,
# ip link set dev eth1 up
# ./testptp -d /dev/ptp2 -P 1
pps for system time request okay
You should be able to see either LD2 or LD5 blink at 1 second interval on AM654x-IDK.
To turn off PPS,
# ./testptp -d /dev/ptp2 -P 0
pps for system time request okay
3.6.3.3.7. XDP¶
The PRU_ICSSG Ethernet driver supports Native XDP as well as Generic XDP. XDP with Zero-copy mode is not supported yet. For detailed setup and how to test XDP please refer to PRU_ICSSG XDP.
3.6.3.3.8. Tips¶
3.6.3.3.8.1. Ethernet PHYs/MDIO bindings¶
The PRU_ICSSG Ethernet driver follows standard Linux DT bindings for MDIO bus, Ethernet controlers and PHYs which can be found at:
The existing TI Ethernet PHYs DT bindings:
3.6.3.3.8.2. Fixed link¶
The Linux PRU_ICSSG Ethernet driver provides support for ‘fixed-link’ MAC-MAC connection support which can be defined following standard Ethernet Controller Generic Binding for each “ethernet-miiX’ ICSSG port.
Note
Fixed link is use-case specific and got limited testing, so should be considered experimental.
Example:
icssg2_emac1: ethernet-mii1 {
phy-mode = "rgmii-rxid";
syscon-rgmii-delay = <&scm_conf 0x4124>;
local-mac-address = [00 00 00 00 00 00];
fixed-link {
speed = <1000>;
full-duplex;
};
};
RGMII Fixed link
In case of RGMII MAC-MAC the ‘phy-mode’ DT property should be specifying properly for RGMII RX/TX delay configuration, taking into account ICSSG HW capability to provide only TX delay (which for some SoCs is not recommended to be disabled). Consult with SoC documentation (Data sheet, User guide) for supported RGMII RX/TX delay configurations.
3.6.3.3.8.3. 100M/10M Half-Duplex¶
The 10/100 half duplex (HD) support depends on HW capability to route PHY output pin (COL) to ICSSG GPI1O pin (PRGx_PRU0/1_GPI10) as input. To indicate that HW supports HD the DT “ti,half-duplex-capable” property shell be added to the corresponding ICSSG “ethernet-mii0” port node.
For example:
icssg0_eth: icssg0-eth {
...
icssg0_emac1: ethernet-mii1 {
...
ti,half-duplex-capable;
};
}
&main_pmx0 {
...
icssg0_rgmii_pins_default: icssg0-rgmii-pins-default {
pinctrl-single,pins = <
...
AM65X_IOPAD(0x026c, PIN_INPUT, 1) /* (AA28) PRG0_PRU1_GPO10.PRG0_PRU1_GPI10 - col */
>;
};
};
3.6.3.3.8.4. MII Support¶
On AM654x-evm the DP83867HM are strapped to RGMII configuration by default. To use MII mode for ICSSG interfaces pinmux settings for MII mode needs to be added to the device tree.
3.6.3.3.9. CPSW / PRU Ethernet Selection¶
This feature is not supported.
3.6.3.3.10. Time Senstive Network (TSN) Offload Support¶
ICSSG Ethernet supports offloading of features such as Enhancements for Scheduled Traffic (EST) and Intersperse Express Traffic (IET) Frame Preemption offload similar to CPSW.
For EST setup refer to kernel_driver_cpsw2g_est and IET configuration refer to kernel_driver_cpsw2g_iet.
For the interface ethX, IET related statistics can be retrieved by using ethtool -S ethX | grep iet command.
3.6.3.3.11. SRAM Requirement¶
The ICSSG Ethernet driver supports multiple instances of ICSSG each of which has two slices. Each ICSSG instance supports two Ethernet interfaces i.e. one per slice.
SRAM Required for each ICSSG instance (per two ports) is as below.
SoC |
Mode |
SRAM Required per ICSSG instance |
|
|---|---|---|---|
AM65X SR 2.0 |
Emac Mode |
192 KB |
|
AM65X SR 2.0 |
Emac Mode + Switch Mode |
256 KB |
|
For each ICSSG instance, the SRAM required needs to be contiguous. PRUETH only uses the required amount of SRAM from the SRAM/MSMC pool. If PRUETH doesn’t get the required amount of SRAM, the prueth_probe() API will return with -ENOMEM error.