| From a0040c0145945d3bd203df8fa97f6dfa819f3f7d Mon Sep 17 00:00:00 2001 |
| From: Vitaly Kuznetsov <vkuznets@redhat.com> |
| Date: Thu, 14 Sep 2017 16:50:14 +0200 |
| Subject: ACPI / PCI: Bail early in acpi_pci_add_bus() if there is no ACPI handle |
| |
| From: Vitaly Kuznetsov <vkuznets@redhat.com> |
| |
| commit a0040c0145945d3bd203df8fa97f6dfa819f3f7d upstream. |
| |
| Hyper-V instances support PCI pass-through which is implemented through PV |
| pci-hyperv driver. When a device is passed through, a new root PCI bus is |
| created in the guest. The bus sits on top of VMBus and has no associated |
| information in ACPI. acpi_pci_add_bus() in this case proceeds all the way |
| to acpi_evaluate_dsm(), which reports |
| |
| ACPI: \: failed to evaluate _DSM (0x1001) |
| |
| While acpi_pci_slot_enumerate() and acpiphp_enumerate_slots() are protected |
| against ACPI_HANDLE() being NULL and do nothing, acpi_evaluate_dsm() is not |
| and gives us the error. It seems the correct fix is to not do anything in |
| acpi_pci_add_bus() in such cases. |
| |
| Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> |
| Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> |
| Cc: Sinan Kaya <okaya@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/pci/pci-acpi.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/pci/pci-acpi.c |
| +++ b/drivers/pci/pci-acpi.c |
| @@ -567,7 +567,7 @@ void acpi_pci_add_bus(struct pci_bus *bu |
| union acpi_object *obj; |
| struct pci_host_bridge *bridge; |
| |
| - if (acpi_pci_disabled || !bus->bridge) |
| + if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge)) |
| return; |
| |
| acpi_pci_slot_enumerate(bus); |
