Slackware 15.0 - Unknown component identified as fd0
 

I've upgraded a PC from 14.1 to 15.0 (Clean install and a new HD) and have a situation where something is being identified as a floppy disk (fd0)

dmesg reports: 0.492124] Floppy drive(s): fd0 is unknown type 13 (usb?)

There is no floppy drive installed
There is no bios floppy option
The kernel "floppy" module is not loaded

Kernel: 5.15.27
MB: GA-78LMT-USB3/GA-78LMT-USB3 rev 5.0
CPU: AMD FX(tm)-6300
Memory: 16GB

I'm not seeing this issue on two other machines running similar hardware, though the Motherboards are rev 6.0

I don't know if this could be the issue, but I've compared lspci output with one of the similar machines and the only unexpected difference I see is with one PCI Bridge listing

Problem Machine:
00:06.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] RS780 PCI to PCI bridge (PCIE port 2)

Other Machine:
00:02.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] RS780 PCI to PCI bridge (ext gfx port 0)

Any insight would be appreciated

Thanks

Wouldn't fd0 be a floppy disks device?

Ordinarily yes, however there isn't a floppy device

Something is being misidentified

I once had that on an old tower machine. There was no floppy drive but the kernel definitely thought there was one. It didn't do any harm though, apart from the silly message.

If it's an old motherboard, does it maybe have a floppy controller?

Hello Hazel,

Yea, there are controllers and they appear to be detected correctly via dmicode, and I have verified the kernel "floppy" module is not loading.

I wish that's all it was

It's reported as a unmounted removable drive, so there are drive mount listings where there shouldn't be.

I can ignore that, however because it's listed as a block device when ever you run anything pertaining to disks

lsblk, fdisk -l, cfdisk etc it takes forever to process because it's trying to access a device which doesn't exist

I think something is being misidentified, and I've tried everything I can think of to try to identify the component (so far) with no success

If you look at /sys/block, can you see any link that could match device fd0? (I have no PC with a floppy here. Cannot check what would be the name)

If yes, assuming the linkname is 'fd', you can check directory /sys/block/fd/device. Maybe there is a file /sys/block/fd/device/inquiry

The content of this file contains a string that could give you a hint about what the device is.

No such luck, already thought of that. In fact I went through pretty much every directory in /sys and got nowhere

BIOS normally has the option to disable a floppy controller.
Note that it may revert to default enabled once the cmos battery runs out.
Only reason why I know this is because I had a board where fd0 just appeared for no reason at all.

Clearly, the solution is to install a floppy drive posthaste.

That was the absolute first thing I looked for.
I went through every option and found nothing relating to floppy, which didn't surprise me since there isn't a floppy IDE port on the board

Nice lol

Came here to applaud this

Update BIOS to most recent one, maybe there's a new version where this is addressed.

Other than that, I'd recommend you a kernel built with CONFIG_BLK_DEV_FD unset.
Slackware has CONFIG_BLK_DEV_FD=y and this is what creates a block device.

I built mine with CONFIG_BLK_DEV_FD not set, and I get no fd0 device even tho I have a controller.

That's a valid suggestion elcore and I don't see why that wouldn't work, but I'd rather not build a custom kernel just for this if possible

The MB in this box is similar to two other boxes except that this the board version is 5.0 where they are 6.0 and are not experiencing the issue.

Currently I'm invested in trying to figure out what/why, but your suggestion is a definite "Plan B"

Thank you

Have you looked at your /etc/fstab file? You might have a legacy reference to /dev/fd0. If you do either comment the line or remove it completely.

Just a thought...