On Fri, Jan 05, 2024 at 08:18:05AM +0000, Shinichiro Kawasaki wrote: > --- a/drivers/platform/x86/p2sb.c > +++ b/drivers/platform/x86/p2sb.c > @@ -150,6 +153,14 @@ static int p2sb_cache_resources(void) > if (!bus) > return -ENODEV; > > + /* > + * When a device with same devfn exists and it is not P2SB, do not > + * touch it. > + */ > + pci_bus_read_config_dword(bus, devfn_p2sb, PCI_CLASS_REVISION, &class); > + if (!PCI_POSSIBLE_ERROR(class) && class >> 8 != P2SB_CLASS_CODE) > + return -ENODEV; > + The function should probably return if PCI_POSSIBLE_ERROR() is true. Also I think you can use PCI_CLASS_MEMORY_OTHER, so how about: if (PCI_POSSIBLE_ERROR(class) || class >> 16 != PCI_CLASS_MEMORY_OTHER) return -ENODEV; Can alternatively use "class >> 8 != PCI_CLASS_MEMORY_OTHER << 8" if you want to ensure the lowest byte is 0x00. Thanks, Lukas
