| Message ID | 20170322010148.32675-1-jlee@suse.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wednesday, March 22, 2017 09:01:48 AM Lee, Chun-Yi wrote: > Just checking the state of container is not enough to confirm that > the whole container is offlined. And why is that so? > Kernel should checks all children's > offline state as the logic in acpi_container_offline(). > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Len Brown <lenb@kernel.org> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Jiri Kosina <jkosina@suse.cz> > Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> > --- > drivers/acpi/scan.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index 1926918..f08ca31 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -260,13 +260,15 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) > static int acpi_scan_hot_remove(struct acpi_device *device) > { > acpi_handle handle = device->handle; > + struct acpi_device *child; > unsigned long long sta; > acpi_status status; > > if (device->handler && device->handler->hotplug.demand_offline > && !acpi_force_hot_remove) { > - if (!acpi_scan_is_offline(device, true)) > - return -EBUSY; > + list_for_each_entry(child, &device->children, node) > + if (!acpi_scan_is_offline(child, false)) > + return -EBUSY; > } else { > int error = acpi_scan_try_to_offline(device); > if (error) > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Mar 22, 2017 at 01:58:30AM +0100, Rafael J. Wysocki wrote: > On Wednesday, March 22, 2017 09:01:48 AM Lee, Chun-Yi wrote: > > Just checking the state of container is not enough to confirm that > > the whole container is offlined. > > And why is that so? > Actually there does not have real kernel issue triggered by this code now. I reviewed code and found the difference between acpi_container_offline(). Considering a container that it includes devices and sub-containers like this: Scope (_SB) Device (MODU) Name (_HID, "ACPI0004") <=== main-container Device (PCIE) Name (_HID, EisaId ("PNP0A08")) Device (SUBM) Name (_HID, "ACPI0004") <=== sub-container Device (MEM0) Name (_HID, EisaId ("PNP0C80")) ... The original code checks the physical nodes on the main container but doesn't check children's physical nodes. So, it may happen the sub-container didn't offline but the offline checking of main container is pass. Please kindly direct me if I misunderstood or missed any detail in the codes about physcial node and container offline. Thank a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 1926918..f08ca31 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -260,13 +260,15 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) static int acpi_scan_hot_remove(struct acpi_device *device) { acpi_handle handle = device->handle; + struct acpi_device *child; unsigned long long sta; acpi_status status; if (device->handler && device->handler->hotplug.demand_offline && !acpi_force_hot_remove) { - if (!acpi_scan_is_offline(device, true)) - return -EBUSY; + list_for_each_entry(child, &device->children, node) + if (!acpi_scan_is_offline(child, false)) + return -EBUSY; } else { int error = acpi_scan_try_to_offline(device); if (error)
Just checking the state of container is not enough to confirm that the whole container is offlined. Kernel should checks all children's offline state as the logic in acpi_container_offline(). Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> --- drivers/acpi/scan.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)