On Sep 3, 2020, 15:35 +0530, Michael S. Tsirkin <
mst@redhat.com>, wrote:
On Sat, Aug 29, 2020 at 01:42:33PM +0530, Ani Sinha wrote:
When ACPI hotplug for the root bus is disabled, the bsel property for that
bus is not set. Please see the following commit:
3d7e78aa7777f ("Introduce a new flag for i440fx to disable PCI hotplug on the root bus").
As a result, when acpi_pcihp_find_hotplug_bus() is called
with bsel set to 0, it may return the root bus. This would be wrong since the
root bus is not hotpluggable. In general, this can potentially happen to other
buses as well.
In this patch, we fix the issue in this function by checking if the bus returned
by the function is actually hotpluggable. If not, we simply return NULL. This
avoids the scenario where we are actually returning a non-hotpluggable bus.
Signed-off-by: Ani Sinha <ani@anisinha.ca>
What exactly are the consequences though?
The root bus might get ejected by the user when it should not if the user does the following:
outl 0xae10 0
outl 0xae08 your_slot
Please see Julia’s comment: