Recently another user asked why they were loading the
fjes module. While I was trying to understand that question, I realized that Linux is also loading the same module for me.
Now, this is the module's information according to
filename: /lib/modules/4.8.0-2-amd64/kernel/drivers/net/fjes/fjes.ko version: 1.1 license: GPL description: FUJITSU Extended Socket Network Device Driver author: Taku Izumi <email@example.com> srcversion: 3411C5E01C7BDA50105EEE7 alias: acpi*:PNP0C02:* depends: intree: Y vermagic: 4.8.0-2-amd64 SMP mod_unload modversions signat: PKCS#7 signer: sig_key: sig_hashalgo: md4
I find this weird. My network adaptor is a Realtek PCI Express card, and it's supported by the module
First thing I checked was if this module had beed added by any particular package. I'm on Debian testing, so I checked that file with
dpkg -S. It is supplied by the kernel image package itself:
# dpkg -S /lib/modules/4.8.0-2-amd64/kernel/drivers/net/fjes/fjes.ko linux-image-4.8.0-2-amd64: /lib/modules/4.8.0-2-amd64/kernel/drivers/net/fjes/fjes.ko
I noticed that the modalias for this module seems very generic. It doesn't even specify a vendor. So I decided to see which devices in
/sys/devices would have a modalias matching this string. I got five results, so I wrote a small script to print a bit more information about them. This is what I got:
./devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/PNP0C02:03 modalias: acpi:PNP0C02: path: \_SB_.PCI0.PDRC physical_node -> ../../../../pnp0/00:08 ./devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C02:01 modalias: acpi:PNP0C02: path: \_SB_.PCI0.LPCB.SIO1 physical_node -> ../../../../../pnp0/00:04 ./devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/INT3F0D:00 modalias: acpi:INT3F0D:PNP0C02: path: \_SB_.PCI0.LPCB.CWDT physical_node -> ../../../../../pnp0/00:03 ./devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C02:02 modalias: acpi:PNP0C02: path: \_SB_.PCI0.LPCB.RMSC physical_node -> ../../../../../pnp0/00:06 ./devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C02:00 modalias: acpi:PNP0C02: path: \_SB_.PCI0.LPCB.LDRC physical_node -> ../../../../../pnp0/00:01
The data above is a dump of the files in
/sys/devices/.... The lines
path are the contents of those files, and
physical_node is the destination of that symbolic link to a directory in
Each one of them is indeed associated with a different physical device, but I have no idea what they are. All I can say is that no other driver module installed on my system has an alias that matches
These are the questions I'm left with:
- What's the meaning of
PCI0.LPCBin the ACPI tree? I infered from the Ubuntu FAQ on ACPI Tricks and Tips that it may be (or should I infer that it should be?) related to a battery. However this is a desktop PC, not a laptopt;
- How come I have three difference devices which all alias to the same thing? Isn't this troubling to the kernel?
- Is the
fjesmodule improperly configured for having such a modalias? Should a bug be opened?