Re: [RFC 2/2] PCI: acpiphp: slowdown hotplug if hotplugging multiple devices at a time

[Fiona Ebner]

Am 13.12.23 um 01:36 schrieb Igor Mammedov:
> previous commit ("PCI: acpiphp: enable slot only if it hasn't been enabled already"
> introduced a workaround to avoid a race between SCSI_SCAN_ASYNC job and
> bridge reconfiguration in case of single HBA hotplug.
> However in virt environment it's possible to pause machine hotplug several
> HBAs and let machine run. That can hit the same race when 2nd hotplugged
> HBA will start re-configuring bridge.
> Do the same thing as SHPC and throttle down hotplug of 2nd and up
> devices within single hotplug event.
> 
> Signed-off-by: Igor Mammedov <imammedo@xxxxxxxxxx>

With only the first patch applied, I could reproduce the issue described
here, i.e. pausing the vCPUs while doing multiple hotplugs and this
patch makes that scenario work too:

Tested-by: Fiona Ebner <f.ebner@xxxxxxxxxxx>