PCI bus detaching when driver crashing?

[Farhan Khan]

Hi all,

I am trying to write the Realtek 8188e (pci) driver for FreeBSD. I am
making slow incremental progress, and having the driver safely exit out (as
opposed to a segfault). I noticed that when the device detaches, due to an
error in the driver, the entire pci bus will also detach! For example, here
is my kernel output:

rtwn0: rtwn_load_firmware: failed to upload firmware rtwn-rtl8188eefw
(error 60)
rtwn0: detached
pci2: detached

The first line is where the code crashes: sys/dev/rtwn/if_rtwn_fw.c line 129
https://github.com/khanzf/freebsd/blob/103c05369b1ced770a2cadc9468e0134c8d9421b/sys/dev/rtwn/if_rtwn_fw.c#L129

Why would this result in the entire pci2 bus detatching? Strangely enough,
I did not have this problem a few months ago, then it suddenly began. This
is significantly slowing down my workflow, and would be nice to have it
resolved. Otherwise, I have to reboot to bring pci2 back up.

Any insight?
Thanks!

Farhan Khan