Hi,
I was trying to setup a router based on Raspberry PI 4B.
Connected two USB adapters, both using the same chipset RTL8153.
This one works as expected
The SFP version doesn't
My transceivers require fixed gigabit speed with autoneg switched off, because they don't support autoneg.
Setting the parameters with ethtool are visible when queried with "ethtool eth2" but neither result in a link nor are they persistent.
Am I missing something? Is this USB SFP adapter supposed to work with OpenWRT?
Gigabit Ethernet has no such parameter.
This would be the expected behavior.
It does not have which parameter? Back in the years where I did SFP driver development for PHY layer it was possible to advertise 10,100,1000 speed using autoneg or not advertise anything and just run the transceiver at a certain speed in forced mode.
Parameters of ethtool seem to reflect that user has a choice.
So, what do I need to do in OpenWRT to run a gigabit transceiver with the aforementioned USB device? Using an electrical transceiver OpenWRT counts a few outgoing packets but never receives an incoming packet.
Does the SFP adapter with your module of choice work in a Windows computer to begin with?
Or any real computer?
Does it work with a fiber module (I guess you run a RJ45 module now)?
Does your module actually support multi speed?
Yes particularly a major Linux distribution. Examining the logs is a good way to tell how to get "Linux compatible" hardware working on OpenWrt.
The one data sheet I found for a RTL8153 (8153-CG) does not have an on chip hardware interface for SERDES / SFP at all, only twisted pair.
Unfortunately not. I just took both adapters and connected them to my MacBook. The simple RJ45 adapter runs just fine, gets a DHCP address from a Draytek Vigor 2865.
The SFP adapter behaves strange. Using the electrical transceiver the Draytek link partner indicates a gigabit link. The green LED of the adapter only lights for a short moment. MacBook does not indicate an ethernet link (as opposed to the Draytek).
Adjusting link advertisement parameters or switching to manual does not change anything.
So I suppose the ethernet link on the CAT cable is established (BTW: same with my VDSL adapter, its LED indicates a successful DSL link). So the module is powered correctly.
For me it seems that the SFP module cannot communicate with the Realtek chip.
Essentially on MacOS and OpenWRT this adapter shows the same behaviour.
Apologies for resuscitating this old thread. I'm eyeing this particular USB/SFP adaptor with the RTL8153. Wondering what SFP's it supports, googling around, that's how I got here. I second what the OP says - the chip datasheet doesn't mention a SERDES or SGMII interface.
I've seen NIC cards for the PCI-e that seem to contain a Broadcom TG3 NIC chip combined with a Marvell switch chip, apparently working as a bridge from whatever PHY the TG3 speaks, to 100/1000 Mbps BASE-X SERDES. Maybe this particular USB dongle employs some such trick as well? If that would be the case, trying to configure particular PHY parameters in the PCI-accessible (or USB-accessible) NIC would at best achieve nothing, or worse, could break communication.
The only way to know for sure would be to crack open the "matchbox" and inspect the chips on the PCB.
A question to the OP, if he still pays attention: what SFP transceivers have you tried? SFP's come in various flavours: SGMII vs. Base-X SERDES, with a standard-compliant MSA SPD EEPROM or custom-coded (often violating the MSA standard) etc... In terms of chances of success, for any noname hardware with an SFP slot, I'd suggest that you try some cheap generic Base-X SERDES SFP with a compliant EEPROM. Cisco-coded modules are generally accepted too, although some of them seem to violate MSA EEPROM compatibility...
Have you tried an "ethtool -m" on the netdevice, with an SFP plugged in?
Also, I've just been made aware of this dongle, reportedly containing an RTL8213B... which appears to be a PHY, or more precisely, a media converter between 10/100/1000 Base-T and 100/1000 fiber. God knows what USB3/ETH MAC it uses, possibly the RTL8153 ? 