In hotplug logic, it always indicates non-specific failure to
platform through _OST when handing acpi hot-remove event failed. Then
platform terminates the hot-remove process but it can not identify
the reason.
Base on current hot-remove code, there have two situations that it
returns busy:
- OSPM try to offline an individual device, but the device offline
function returns busy.
- When the ejection event is applied to an "not offlined yet" container.
OSPM send kobject change event to userspace and returns busy.
Both of them will returns -EBUSY to acpi device hotplug function then
hotplug function indicates non-specific failure to platform just like
any other error, e.g. -ENODEV or -EIO.
The benefit to platform for identifying the OS busy state is that
platform can be applied different approach to handle the busy but
not just terminate the hot-remove process by unknow reason. For
example, platform can wait for a while then triggers hot-remove
again.
This RFC patch adds one more parameter to the handler function of
acpi generic hotplug event to give the function a chance to propose
the return code of _OST. In this case, it sets ost return code to
ACPI_OST_SC_DEVICE_BUSY when the acpi hot remove function returns
-EBUSY.
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Len Brown <[email protected]>
Signed-off-by: "Lee, Chun-Yi" <[email protected]>
---
drivers/acpi/scan.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 2433569..d4aae9f 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -374,8 +374,11 @@ static int acpi_scan_bus_check(struct acpi_device *adev)
return 0;
}
-static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
+static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type,
+ u32 *ost_code)
{
+ int error = -EINVAL;
+
switch (type) {
case ACPI_NOTIFY_BUS_CHECK:
return acpi_scan_bus_check(adev);
@@ -389,9 +392,11 @@ static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
}
acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
- return acpi_scan_hot_remove(adev);
+ error = acpi_scan_hot_remove(adev);
+ if (error == -EBUSY && ost_code)
+ *ost_code = ACPI_OST_SC_DEVICE_BUSY;
}
- return -EINVAL;
+ return error;
}
void acpi_device_hotplug(struct acpi_device *adev, u32 src)
@@ -413,7 +418,7 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
if (adev->flags.is_dock_station) {
error = dock_notify(adev, src);
} else if (adev->flags.hotplug_notify) {
- error = acpi_generic_hotplug_event(adev, src);
+ error = acpi_generic_hotplug_event(adev, src, &ost_code);
if (error == -EPERM) {
ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
goto err_out;
--
2.10.2
On Wed, Jun 7, 2017 at 9:07 AM, Lee, Chun-Yi <[email protected]> wrote:
> In hotplug logic, it always indicates non-specific failure to
> platform through _OST when handing acpi hot-remove event failed. Then
> platform terminates the hot-remove process but it can not identify
> the reason.
>
> Base on current hot-remove code, there have two situations that it
> returns busy:
> - OSPM try to offline an individual device, but the device offline
> function returns busy.
> - When the ejection event is applied to an "not offlined yet" container.
> OSPM send kobject change event to userspace and returns busy.
>
> Both of them will returns -EBUSY to acpi device hotplug function then
> hotplug function indicates non-specific failure to platform just like
> any other error, e.g. -ENODEV or -EIO.
>
> The benefit to platform for identifying the OS busy state is that
> platform can be applied different approach to handle the busy but
> not just terminate the hot-remove process by unknow reason. For
> example, platform can wait for a while then triggers hot-remove
> again.
>
> This RFC patch adds one more parameter to the handler function of
> acpi generic hotplug event to give the function a chance to propose
> the return code of _OST. In this case, it sets ost return code to
> ACPI_OST_SC_DEVICE_BUSY when the acpi hot remove function returns
> -EBUSY.
> -static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
> +static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type,
> + u32 *ost_code)
> {
> + int error = -EINVAL;
> +
> switch (type) {
> case ACPI_NOTIFY_BUS_CHECK:
> return acpi_scan_bus_check(adev);
> @@ -389,9 +392,11 @@ static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
> }
> acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
> ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> - return acpi_scan_hot_remove(adev);
> + error = acpi_scan_hot_remove(adev);
> + if (error == -EBUSY && ost_code)
> + *ost_code = ACPI_OST_SC_DEVICE_BUSY;
> }
> - return -EINVAL;
> + return error;
> }
>
> void acpi_device_hotplug(struct acpi_device *adev, u32 src)
> @@ -413,7 +418,7 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
> if (adev->flags.is_dock_station) {
> error = dock_notify(adev, src);
> } else if (adev->flags.hotplug_notify) {
> - error = acpi_generic_hotplug_event(adev, src);
> + error = acpi_generic_hotplug_event(adev, src, &ost_code);
> if (error == -EPERM) {
> ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
Looking again to the code I still think you may easily do all stuff
here in shorter and cleaner manner.
Do we anticipate that there will be more callers that would like to
get ost_code for one specific type of event?
Above intrusion to the acpi_generic_hotplug_event() looks to me like
non-generic hack.
--
With Best Regards,
Andy Shevchenko
On Wed, Jun 07, 2017 at 11:50:13AM +0300, Andy Shevchenko wrote:
> On Wed, Jun 7, 2017 at 9:07 AM, Lee, Chun-Yi <[email protected]> wrote:
> > In hotplug logic, it always indicates non-specific failure to
> > platform through _OST when handing acpi hot-remove event failed. Then
> > platform terminates the hot-remove process but it can not identify
> > the reason.
> >
> > Base on current hot-remove code, there have two situations that it
> > returns busy:
> > - OSPM try to offline an individual device, but the device offline
> > function returns busy.
> > - When the ejection event is applied to an "not offlined yet" container.
> > OSPM send kobject change event to userspace and returns busy.
> >
> > Both of them will returns -EBUSY to acpi device hotplug function then
> > hotplug function indicates non-specific failure to platform just like
> > any other error, e.g. -ENODEV or -EIO.
> >
> > The benefit to platform for identifying the OS busy state is that
> > platform can be applied different approach to handle the busy but
> > not just terminate the hot-remove process by unknow reason. For
> > example, platform can wait for a while then triggers hot-remove
> > again.
> >
> > This RFC patch adds one more parameter to the handler function of
> > acpi generic hotplug event to give the function a chance to propose
> > the return code of _OST. In this case, it sets ost return code to
> > ACPI_OST_SC_DEVICE_BUSY when the acpi hot remove function returns
> > -EBUSY.
>
> > -static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
> > +static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type,
> > + u32 *ost_code)
> > {
> > + int error = -EINVAL;
> > +
> > switch (type) {
> > case ACPI_NOTIFY_BUS_CHECK:
> > return acpi_scan_bus_check(adev);
> > @@ -389,9 +392,11 @@ static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
> > }
> > acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
> > ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> > - return acpi_scan_hot_remove(adev);
> > + error = acpi_scan_hot_remove(adev);
> > + if (error == -EBUSY && ost_code)
> > + *ost_code = ACPI_OST_SC_DEVICE_BUSY;
> > }
> > - return -EINVAL;
> > + return error;
> > }
> >
> > void acpi_device_hotplug(struct acpi_device *adev, u32 src)
> > @@ -413,7 +418,7 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
> > if (adev->flags.is_dock_station) {
> > error = dock_notify(adev, src);
> > } else if (adev->flags.hotplug_notify) {
> > - error = acpi_generic_hotplug_event(adev, src);
> > + error = acpi_generic_hotplug_event(adev, src, &ost_code);
> > if (error == -EPERM) {
> > ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
>
> Looking again to the code I still think you may easily do all stuff
> here in shorter and cleaner manner.
> Do we anticipate that there will be more callers that would like to
> get ost_code for one specific type of event?
> Above intrusion to the acpi_generic_hotplug_event() looks to me like
> non-generic hack.
>
Thanks for your suggestion, I will use switch-case to handle it in
next version.
I checked the ACPI spec and code path of other events:
- For the standard nodification, the possible return value:
- ACPI_NOTIFY_BUS_CHECK: acpi_scan_bus_check() returns 0 or -ENODEV
- ACPI_NOTIFY_DEVICE_CHECK: acpi_scan_device_check() returns 0, -ENODEV or -EALREADY
So, standard notification needs only Success(0) or Non-specific failure(1)
- For docker, currently the dock_notify() only returns 0 or -ENODEV.
But, actually the handle_eject_request() may returns 0 or -EBUSY, but
dock_notify() ignored it.
If there have any machines that it has _OST for dock device, we should
consider to return ACPI_OST_SC_DEVICE_BUSY to dock. Currently I didn't
see benefit on this.
- For additional notify handlers
I only found acpi_pci_root_scan_dependent() that it always returns 0.
- There have ACPI_OST_EC_OSPM_INSERTION(0x200) that OSPM didn't support
It's definded in "Insertion Processing (Source Event: 0x200) Status Codes"
in spec. It will use specific _OST event.
The event types are used by different acpi devices type. And, there have
the insertion event may shows in the future. I will use a switch-case to
handle the change in acpi_generic_hotplug_event().
Thanks a lot!
Joey Lee