On Sun, 30 Aug 2026 17:35:57 +0200, Al Ma wrote: > > Please try unloading the ee1004 driver, then running i2cdetect again. > > Here we go: > > # modprobe -r ee1004 && i2cdetect -y 0 && modprobe ee1004 > 0 1 2 3 4 5 6 7 8 9 a b c d e f > 00: 08 -- -- -- -- -- -- -- > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 40: -- -- -- -- 44 -- -- -- -- -- -- -- -- -- -- -- > 50: -- -- -- -- -- -- 56 -- -- -- -- -- -- -- -- -- > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 70: -- -- -- -- -- -- -- -- > > What next?
This confirms my guess that the device at 0x56 is not an SPD EEPROM. Next steps would be as follows: * Short term, you want to blacklist the ee1004 driver on your system. It is not a good idea to load a driver which binds to the wrong device. * Still short term, we should look into the ee1004 auto-detection logic and see it it can be made more reliable. * Mid term, we may want to add a kernel option to disable automatic probing of SPD EEPROMs. I seem to recall some proposals but it looks like they never made it into the upstream kernel. I'm not sure if this should be a system-wide switch (handled by the i2c core) or a per-driver setting (e.g. a new flag in i2c-i801's disable_features parameter). * Still mid term, we probably want to blacklist SPD probing explicitly for your motherboard (we'll need to know the contents of /sys/devices/virtual/dmi/id/board_vendor and /sys/devices/virtual/dmi/id/board_name on your system). Maybe this can be implemented as an empty entry in mux_dmi_table (as in, we know the board requires multiplexing, but we don't know yet to implement it on that board). * Long term, we need the hardware vendor to provide technical information about the board so that we can implement SMBus multiplexing support in the i2c-i801 driver (if that's really how things are implemented on your board - that's only a guess from me at this point). Asus provided information about their Z8 series long ago and I was able to add support for it back then. It would be wonderful if they could provide similar information about the WS C422 PRO/SE so that a kernel developer can add support. -- Jean Delvare SUSE L3 Support
