On Wed, Sep 19, 2018 at 11:44:02PM +0200, Rafael J. Wysocki wrote: > On Wed, Sep 19, 2018 at 1:32 PM Mika Westerberg > <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > > > HP 6730b laptop has an ethernet NIC connected to one of the PCIe root > > ports. The root ports itself are native PCIe hotplug capable. Now, > > during boot after PCI devices are scanned the BIOS triggers ACPI bus > > check directly to the NIC: > > > > [ 0.942239] ACPI: \_SB_.PCI0.RP06.NIC_: Bus check in hotplug_event() > > > > It is not clear why it is sending bus check but regardless the ACPI > > hotplug notify handler calls enable_slot() directly (instead of going > > through acpiphp_check_bridge() as there is no bridge) which ends up > > handling special case for non-hotplug bridges with native PCIe hotplug. > > This results a crash of some kind but the reporter only sees black > > screen so it is hard to figure out the exact spot and what actually > > happens. Based on few fix proposals it was tracked to crash somewhere > > inside pci_assign_unassigned_bridge_resources(). > > > > In any case we should not really be in that special branch at all > > because the ACPI notify happened to a slot that is not a PCI bridge (it > > is just a regular PCI device). > > > > Fix this so that we only go to that special branch if we are calling > > enable_slot() for a bridge (e.g the ACPI notification was for the bridge). > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=201127 > > Fixes: 84c8b58ed3ad ACPI / hotplug / PCI: Don't scan bridges managed by native hotplug > > Reported-by: Peter Anemone <peter.anemone@xxxxxxxxx> > > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > --- > > drivers/pci/hotplug/acpiphp_glue.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > > index ef0b1b6ba86f..fa2d82ae6ccd 100644 > > --- a/drivers/pci/hotplug/acpiphp_glue.c > > +++ b/drivers/pci/hotplug/acpiphp_glue.c > > @@ -457,17 +457,20 @@ static void acpiphp_native_scan_bridge(struct pci_dev *bridge) > > /** > > * enable_slot - enable, configure a slot > > * @slot: slot to be enabled > > + * @bridge: Bridge if the hotplug was directly to the bridge. %NULL > > + * otherwise. > > * > > * This function should be called per *physical slot*, > > * not per each slot object in ACPI namespace. > > */ > > -static void enable_slot(struct acpiphp_slot *slot) > > +static void enable_slot(struct acpiphp_slot *slot, > > + const struct acpiphp_bridge *bridge) > > { > > struct pci_dev *dev; > > struct pci_bus *bus = slot->bus; > > struct acpiphp_func *func; > > > > - if (bus->self && hotplug_is_native(bus->self)) { > > + if (bridge && bus->self && hotplug_is_native(bus->self)) { > > AFAICS "bridge" is used as a bool here. What would be wrong with > using the bool data type for this arg? Nothing wrong with that :) I'll change it. Thanks!
