Hy
I use a sfp gpon onu brand fs.
I can access by ssh into the module sfp.
But i need to plug fiber with signal.
I would like to access without beeing obliged to plug fiber.
I began by modifying the DTS :
sfp1: sfp-1 {
compatible = "sff,sfp";
i2c-bus = <&i2c_sfp1>;
los-gpios = <&pio 46 GPIO_ACTIVE_HIGH>;
mod-def0-gpios = <&pio 49 GPIO_ACTIVE_LOW>;
tx-disable-gpios = <&pio 20 GPIO_ACTIVE_HIGH>;
tx-fault-gpios = <&pio 7 GPIO_ACTIVE_HIGH>;
maximum-power-milliwatt = <3000>;
};
los-gpios = <&pio 46 GPIO_ACTIVE_HIGH> ====> <&pio 46 GPIO_ACTIVE_LOW>
It works.
But when i plug the fiber, i lost the connexion ssh.
Is it possible to bypass or block the los gpios to low?
Or any ideas
frank-w
October 13, 2023, 2:58pm
2
you could add an dt overlay which you can load when config is needed without fiber connected and leave it when not
1 Like
ericwoud
October 13, 2023, 3:32pm
3
Choose a gpio pin on the gpio header and set/clear it with a jumper …
1 Like
Hy.
Thank you to answer me
I think the problem will stay.
if i keep the original number gpio, when i insert a fiber with signal, the state of the gpio change.
Hy,
i tried to select a pin from the gpio header for each
And change the pin in the DTS.
but no jumper on the header.
For example : los-gpios = <&pio 8 GPIO_ACTIVE_LOW> .
Sometine, the sfp lan works but not the sfp wan.
Another time, it’s the sfp wan it works and not the sfp lan.
I will try with all free pins
frank-w
October 14, 2023, 6:05am
6
Yes that is the purpose of the los gpio,it indicates loss of signal…if there is a los signal the interface goes down.
So los needs to be off to get interface itself working.
i change the pin for the gpio los :
sfp1: sfp-1 {
compatible = "sff,sfp";
i2c-bus = <&i2c_sfp1>;
- los-gpios = <&pio 46 GPIO_ACTIVE_HIGH>;
+ los-gpios = <&pio 8 GPIO_ACTIVE_HIGH>;
mod-def0-gpios = <&pio 49 GPIO_ACTIVE_LOW>;
tx-disable-gpios = <&pio 20 GPIO_ACTIVE_HIGH>;
tx-fault-gpios = <&pio 7 GPIO_ACTIVE_HIGH>;
@@ -126,7 +126,7 @@
sfp2: sfp-2 {
compatible = "sff,sfp";
i2c-bus = <&i2c_sfp2>;
- los-gpios = <&pio 31 GPIO_ACTIVE_HIGH>;
+ los-gpios = <&pio 63 GPIO_ACTIVE_HIGH>;
mod-def0-gpios = <&pio 47 GPIO_ACTIVE_LOW>;
tx-disable-gpios = <&pio 15 GPIO_ACTIVE_HIGH>;
tx-fault-gpios = <&pio 48 GPIO_ACTIVE_HIGH>;
It seems to work.
I continue to test and see in the long term
frank-w
October 15, 2023, 3:47pm
8
have you tried simply disable the los-gpios (commenting out via //)? or adding a quirk for ignoring the los gpio…but then of course the tx is always enabled which is not the best way…but mapping los-gpio to another gpio not associated with the sfp results in same wrong behaviour
1 Like
Hy.
I tried to comment the los gpios line, but it wasn’t good
I change to use gpio pin free i won’t use and it works.
I will see in long term if everything go on working.
Thank you again
frank-w
January 4, 2026, 12:30pm
10
i tried to do same on R4 with an ODI GPON-SFP
+++ b/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi
@@ -86,7 +86,9 @@ sfp1: sfp1 {
i2c-bus = <&i2c_sfp1>;
maximum-power-milliwatt = <3000>;
- los-gpios = <&pio 54 GPIO_ACTIVE_HIGH>;
+ //los-gpios = <&pio 54 GPIO_ACTIVE_HIGH>;
+ los-gpios = <&pio 52 GPIO_ACTIVE_LOW>; //pin 26 to be connected to gnd to be active
mod-def0-gpios = <&pio 82 GPIO_ACTIVE_LOW>;
rate-select0-gpios = <&pio 21 GPIO_ACTIVE_LOW>;
tx-disable-gpios = <&pio 70 GPIO_ACTIVE_HIGH>;
ethtool itself looks good, but i cannot access the system on the stick
root@bpi-r4-v11:~
# dmesg | grep -i sfp
[ 0.000000] Machine model: Banana Pi BPI-R4 (2x SFP+)
[ 1.302580] sfp sfp1: Host maximum power 3.0W
[ 1.303418] sfp sfp2: Host maximum power 3.0W
[ 1.622789] sfp sfp1: module ODI DFP-34G-2C2 rev sn GPON25101036 dc 251018
[ 1.634117] sfp sfp2: module CISCO-FINISAR FTLX8571D3BCL-C2 rev A sn S2209167650 dc 220916
root@bpi-r4-v11:~
# ethtool eth2
Settings for eth2:
Supported ports: [ FIBRE ]
Supported link modes: 1000baseX/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 1000baseX/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: Unknown!
Duplex: Unknown! (255)
Auto-negotiation: on
Port: FIBRE
PHYAD: 0
Transceiver: internal
Current message level: 0x000000ff (255)
drv probe link timer ifdown ifup rx_err tx_err
Link detected: no
root@bpi-r4-v11:~
# ethtool -m eth2
Identifier : 0x03 (SFP)
Extended identifier : 0x04 (GBIC/SFP defined by 2-wire interface ID)
Connector : 0x01 (SC)
Transceiver codes : 0x00 0x00 0x00 0x02 0x22 0x00 0x01 0x00 0x00
Transceiver type : Ethernet: 1000BASE-LX
Transceiver type : FC: intermediate distance (I)
Transceiver type : FC: Longwave laser (LC)
Transceiver type : FC: Single Mode (SM)
Encoding : 0x01 (8B/10B)
BR, Nominal : 1300MBd
Rate identifier : 0x00 (unspecified)
Length (SMF,km) : 20km
Length (SMF) : 20000m
Length (50um) : 0m
Length (62.5um) : 0m
Length (Copper) : 0m
Length (OM3) : 0m
Laser wavelength : 1310nm
Vendor name : ODI
Vendor OUI : 00:00:00
Vendor PN : DFP-34G-2C2
Vendor rev :
Option values : 0x00 0x1a
Option : RX_LOS implemented
Option : TX_FAULT implemented
Option : TX_DISABLE implemented
BR margin, max : 0%
BR margin, min : 0%
Vendor SN : GPON25101036
Date code : 251018
root@bpi-r4-v11:~
# ip a s eth2
5: eth2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 9e:93:3f:bd:42:da brd ff:ff:ff:ff:ff:ff
inet 192.168.1.5/24 scope global eth2
valid_lft forever preferred_lft forever
root@bpi-r4-v11:~
# ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
From 192.168.1.5 icmp_seq=1 Destination Host Unreachable
^C
--- 192.168.1.1 ping statistics ---
4 packets transmitted, 0 received, +1 errors, 100% packet loss, time 3146ms
pipe 4
ericwoud
January 5, 2026, 7:19am
11
Los active low, so to fake a link detected the GPIO needs to be high?
frank-w
January 5, 2026, 10:39am
12
yes you are right, but unfortunately it does not matter as interface does not get logical up.
# ip a s eth2
5: eth2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether be:2b:95:ce:44:fd brd ff:ff:ff:ff:ff:ff
inet 192.168.1.5/24 scope global eth2
valid_lft forever preferred_lft forever
root@bpi-r4-v11:~
# ethtool eth2
Settings for eth2:
Supported ports: [ FIBRE ]
Supported link modes: 1000baseX/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 1000baseX/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: Unknown!
Duplex: Unknown! (255)
Auto-negotiation: on
Port: FIBRE
PHYAD: 0
Transceiver: internal
Current message level: 0x000000ff (255)
drv probe link timer ifdown ifup rx_err tx_err
Link detected: no
root@bpi-r4-v11:~
# ethtool -m eth2
Identifier : 0x03 (SFP)
Extended identifier : 0x04 (GBIC/SFP defined by 2-wire interface ID)
Connector : 0x01 (SC)
Transceiver codes : 0x00 0x00 0x00 0x02 0x22 0x00 0x01 0x00 0x00
Transceiver type : Ethernet: 1000BASE-LX
Transceiver type : FC: intermediate distance (I)
Transceiver type : FC: Longwave laser (LC)
Transceiver type : FC: Single Mode (SM)
Encoding : 0x01 (8B/10B)
BR, Nominal : 1300MBd
Rate identifier : 0x00 (unspecified)
Length (SMF,km) : 20km
Length (SMF) : 20000m
Length (50um) : 0m
Length (62.5um) : 0m
Length (Copper) : 0m
Length (OM3) : 0m
Laser wavelength : 1310nm
Vendor name : ODI
Vendor OUI : 00:00:00
Vendor PN : DFP-34G-2C2
Vendor rev :
Option values : 0x00 0x1a
Option : RX_LOS implemented
Option : TX_FAULT implemented
Option : TX_DISABLE implemented
BR margin, max : 0%
BR margin, min : 0%
Vendor SN : GPON25101036
Date code : 251018
