Re: USB controller enumeration on APU3 is random since the update to kernel 6.6

[Sam Kuper]

On 18 July 2024 09:53:14 UTC, Florian Eckert <fe at dev.tdt.de> wrote:
> 
> I found a commit [1] in the Linux kernel that makes the USB
> controller probing asynchronous and therefore not deterministic as
> before. I have reverted the commit on my build and now nothing
> changes in the controller numbering. This is not a solution, but
> I now know what the problem is. With a new kernel, the numbering
> can be completely different again.
> 
> From my point of view, that's a general problem, that USB controller
> does not have a fix sysfs path. In my case, I explicitly refer to
> a USB device sysfs path in the network configuration that the
> modemmanager should use. I can't work with serial number, pid, vid.
> I think also the udev service will also not help there.
> 
> The question is how to get a unambiguous that is the same after every
> boot even if the kernel changes the probing behavior. On the PCI bus
> there is always unambiguous number.
> 
> [...]
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=69a1c9a9b273271f2a2674bcc117336a9bb0a4b4


Might it be best to file a bug report against the Linux kernel?

After all, the commit message suggests the developer didn't anticipate this commit causing breakage.

Yet it seems the commit is causing serious breakage, likely to stop many people's routers, PCs or other devices to stop being able to use peripherals (network adapters, printers, cameras, who knows what else?) as expected, with no easy workaround.

Sorry if I've misunderstood. 

Sam