On Saturday, June 15, 2013 03:28:01 AM Jiang Liu wrote: > Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=56531 for > more information. > > This issue is caused by differences in PCI resource assignment between > boot time and runtime hotplug. On x86 platforms, OS respects PCI > resource assignment from BIOS and only reassign resources for unassigned > BARs at boot time. But with acpiphp, it ignores BIOS resource assignment > and reassign all resources by itself. > > If we have enough resources, reassigning all PCI resources should work > too, but it may fail if we are under resource constraints. On the other > handle, current PCI MMIO alignment algorithm may waste huge MMIO address > space if we have some PCI devices with huge MMIO BARs. > > On this Sony laptop, BIOS allocates limited MMIO resources for the dock > station and the dock station has a gfx which has a 256MB MMIO BAR. > So current acpiphp driver fails to allocate resources for most devices > on the dock station. > > So change acpiphp driver to follow boot time behavior to respect BIOS > resource assignment. > > Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx> > Reported-by: Alexander E. Patrakov <patrakov@xxxxxxxxx> > Tested-by: Alexander E. Patrakov <patrakov@xxxxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxx> > Cc: linux-acpi@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: <stable@xxxxxxxxxxxxxxx> The code is fine as far as I'm concerned, but I have one request. -> > --- > drivers/pci/hotplug/acpiphp_glue.c | 7 +++++-- > drivers/pci/pci.h | 5 +++++ > drivers/pci/setup-bus.c | 8 ++++---- > 3 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index a65203b..f4a53e9 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -687,6 +687,7 @@ static int __ref enable_device(struct acpiphp_slot *slot) > struct pci_bus *bus = slot->bridge->pci_bus; > struct acpiphp_func *func; > int num, max, pass; > + LIST_HEAD(add_list); > > if (slot->flags & SLOT_ENABLED) > goto err_exit; > @@ -711,13 +712,15 @@ static int __ref enable_device(struct acpiphp_slot *slot) > max = pci_scan_bridge(bus, dev, max, pass); > if (pass && dev->subordinate) { > check_hotplug_bridge(slot, dev); > - pci_bus_size_bridges(dev->subordinate); Please add a comment explaining why we need to do this here. > + pcibios_resource_survey_bus(dev->subordinate); > + __pci_bus_size_bridges(dev->subordinate, > + &add_list); > } > } > } > } > > - pci_bus_assign_resources(bus); > + __pci_bus_assign_resources(bus, &add_list, NULL); > acpiphp_sanitize_bus(bus); > acpiphp_set_hpp_values(bus); > acpiphp_set_acpi_region(slot); > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 68678ed..d1182c4 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -202,6 +202,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > struct resource *res, unsigned int reg); > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > void pci_configure_ari(struct pci_dev *dev); > +void __ref __pci_bus_size_bridges(struct pci_bus *bus, > + struct list_head *realloc_head); > +void __ref __pci_bus_assign_resources(const struct pci_bus *bus, > + struct list_head *realloc_head, > + struct list_head *fail_head); > > /** > * pci_ari_enabled - query ARI forwarding status > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 16abaaa..d254e23 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1044,7 +1044,7 @@ handle_done: > ; > } > > -static void __ref __pci_bus_size_bridges(struct pci_bus *bus, > +void __ref __pci_bus_size_bridges(struct pci_bus *bus, > struct list_head *realloc_head) > { > struct pci_dev *dev; > @@ -1115,9 +1115,9 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_bus_size_bridges); > > -static void __ref __pci_bus_assign_resources(const struct pci_bus *bus, > - struct list_head *realloc_head, > - struct list_head *fail_head) > +void __ref __pci_bus_assign_resources(const struct pci_bus *bus, > + struct list_head *realloc_head, > + struct list_head *fail_head) > { > struct pci_bus *b; > struct pci_dev *dev; Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
