From: Vitaly Kuznetsov Date: Thu, 14 Sep 2017 14:50:14 +0000 (+0200) Subject: ACPI / PCI: Bail early in acpi_pci_add_bus() if there is no ACPI handle X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ff28e5cc58c2015ae65ad0070a3c90898f69aa3b;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git ACPI / PCI: Bail early in acpi_pci_add_bus() if there is no ACPI handle 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 Signed-off-by: Bjorn Helgaas Cc: Sinan Kaya Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index a8da543b3814..4708eb9df71b 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -624,7 +624,7 @@ void acpi_pci_add_bus(struct pci_bus *bus) 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);