On Fri, Apr 28, 2017 at 7:56 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > Hi Kyle, > > On Wed, Apr 26, 2017 at 5:56 PM, Kyle Gale <kylewgale@xxxxxxxxx> wrote: >> Hi, >> >> >> >> 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. > > Ideally, the PCI hotplug code would automatically remove the PCI > device files when you remove the physical device, and it would also > automatically scan the device when you plug it back in. > > You shouldn't need to do either the remove or the rescan manually via sysfs. > > Apparently your system does actually support hotplug. Do you have it > enabled in the kernel? The "lspci -vv" output, dmesg output, and your > .config would help answer these questions. could be BIOS does set correct padding when card is not present. but if the slot really support pcie hotplug aka pcie slot cap/hp is present, current code should handle that case, and increase root port bridge resource directly. Yinghai
