| Message ID | 1499297.p2drhZLZaT@vostro.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
[+cc Lorenzo, tiagdtd-lava] On Wed, May 20, 2015 at 02:14:13AM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > If the ignore_hotplug flag is set for a PCI device without an ACPI > companion and a bus check notification is received for an ancestor > bridge that is not the device's parent, ACPIPHP will ignore that > flag. > > Namely, in that case acpiphp_check_bridge() is called for the target > bridge and if all of the devices immediately below the bridge are > still present, trim_stale_devices() will be called for each of them. > That function recursively walks the hierarchy downwards and removes > device objects corresponding to devices that don't appear to be > present any more. Unfortunately, it only checks ignore_hotplug > for devices having ACPI companions, so it will remove the others > (if they don't respond) regardless of the ignore_hotplug value. > > Fix the problem by making trim_stale_devices() take ignore_hotplug > into consideration regardless of whether or not an ACPI companion > is present for the device it has been called for. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Applied to pci/hotplug for v4.2, thanks! I cc'd Lorenzo and tiagdtd-lava in hopes they can test this patch and see whether it resolves https://bugzilla.kernel.org/show_bug.cgi?id=61891 . The branch with this patch applied is here: https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/hotplug > --- > > This may fix BZ61891, but even if it doesn't, the bug is quite obvious to me. > > Should be applicable since commit b440bde74f04 (PCI: Add pci_ignore_hotplug() > to ignore hotplug events for a device) which shipped in 3.17. > > --- > drivers/pci/hotplug/acpiphp_glue.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c > +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c > @@ -632,15 +632,14 @@ static void trim_stale_devices(struct pc > { > struct acpi_device *adev = ACPI_COMPANION(&dev->dev); > struct pci_bus *bus = dev->subordinate; > - bool alive = false; > + bool alive = dev->ignore_hotplug; > > if (adev) { > acpi_status status; > unsigned long long sta; > > status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); > - alive = (ACPI_SUCCESS(status) && device_status_valid(sta)) > - || dev->ignore_hotplug; > + alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta)); > } > if (!alive) > alive = pci_device_is_present(dev); > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday, May 22, 2015 04:44:16 PM Bjorn Helgaas wrote: > [+cc Lorenzo, tiagdtd-lava] > > On Wed, May 20, 2015 at 02:14:13AM +0200, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > If the ignore_hotplug flag is set for a PCI device without an ACPI > > companion and a bus check notification is received for an ancestor > > bridge that is not the device's parent, ACPIPHP will ignore that > > flag. > > > > Namely, in that case acpiphp_check_bridge() is called for the target > > bridge and if all of the devices immediately below the bridge are > > still present, trim_stale_devices() will be called for each of them. > > That function recursively walks the hierarchy downwards and removes > > device objects corresponding to devices that don't appear to be > > present any more. Unfortunately, it only checks ignore_hotplug > > for devices having ACPI companions, so it will remove the others > > (if they don't respond) regardless of the ignore_hotplug value. > > > > Fix the problem by making trim_stale_devices() take ignore_hotplug > > into consideration regardless of whether or not an ACPI companion > > is present for the device it has been called for. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Applied to pci/hotplug for v4.2, thanks! > > I cc'd Lorenzo and tiagdtd-lava in hopes they can test this patch and see > whether it resolves https://bugzilla.kernel.org/show_bug.cgi?id=61891 . > > The branch with this patch applied is here: > https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/hotplug Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -632,15 +632,14 @@ static void trim_stale_devices(struct pc { struct acpi_device *adev = ACPI_COMPANION(&dev->dev); struct pci_bus *bus = dev->subordinate; - bool alive = false; + bool alive = dev->ignore_hotplug; if (adev) { acpi_status status; unsigned long long sta; status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); - alive = (ACPI_SUCCESS(status) && device_status_valid(sta)) - || dev->ignore_hotplug; + alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta)); } if (!alive) alive = pci_device_is_present(dev);