Can someone help me understand why I need to remove my stale PCI device files from the tree if I want to properly get my device re-initialized after unplugging and reinserting?

For example, I turn on my system with my PCI device plugged in. All is fine. I unplug it, plug it back in, and rescan (echo 1 > /sys/bus/pci/devices/rescan) and end up in this state where my BAR0 is not set, and other things are not entirely correct.

But if I do a remove (echo 1 > /sys/bus/pci/devices/xxxx/xx.x/remove) of the port, it then properly re-initializes my device when I do a rescan.

Why does it not suffice to simply do a rescan? Does the rescan skip some step if it finds that the device is already in the PCI tree? It's not as if the rescan completely skips the device if I don't do a remove, it just doesn't do all of the initialization.

I assume you remove it before you take the pci card out. I also assume the board has full support for this task.

I think this link has the clues you are asking about. https://stackoverflow.com/questions/...an-of-pcie-bus