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 unknown 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.
v2:
Do not overwrite ost code in acpi_generic_hotplug_event(). Move
the "error code to ost code" logic to a help function.
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Signed-off-by: "Lee, Chun-Yi" <[email protected]>
---
drivers/acpi/scan.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 2433569..e407eed 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -394,6 +394,20 @@ static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
return -EINVAL;
}
+static int acpi_ost_status_code(u32 src, int error)
+{
+ switch (src) {
+ case ACPI_NOTIFY_EJECT_REQUEST:
+ case ACPI_OST_EC_OSPM_EJECT:
+ if (error == -EPERM)
+ return ACPI_OST_SC_EJECT_NOT_SUPPORTED;
+ else if (error == -EBUSY)
+ return ACPI_OST_SC_DEVICE_BUSY;
+ break;
+ }
+ return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS;
+}
+
void acpi_device_hotplug(struct acpi_device *adev, u32 src)
{
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
@@ -414,10 +428,6 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
error = dock_notify(adev, src);
} else if (adev->flags.hotplug_notify) {
error = acpi_generic_hotplug_event(adev, src);
- if (error == -EPERM) {
- ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
- goto err_out;
- }
} else {
int (*notify)(struct acpi_device *, u32);
@@ -433,9 +443,8 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
else
goto out;
}
- if (!error)
- ost_code = ACPI_OST_SC_SUCCESS;
+ ost_code = acpi_ost_status_code(src, error);
err_out:
acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
--
2.10.2
On Fri, Jun 9, 2017 at 1:54 PM, 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 unknown 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.
Below looks better for my taste.
See also comments.
> +static int acpi_ost_status_code(u32 src, int error)
> +{
> + switch (src) {
> + case ACPI_NOTIFY_EJECT_REQUEST:
> + case ACPI_OST_EC_OSPM_EJECT:
> + if (error == -EPERM)
> + return ACPI_OST_SC_EJECT_NOT_SUPPORTED;
> + else if (error == -EBUSY)
Redundant else...
> + return ACPI_OST_SC_DEVICE_BUSY;
Perhaps switch case here as well?
switch (error) {
case -EPERM;
return X;
case -EBUSY:
return Y;
}
> + break;
> + }
> + return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS;
> +}
> + ost_code = acpi_ost_status_code(src, error);
> err_out:
I guess you need to swap those lines.
> acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
--
With Best Regards,
Andy Shevchenko
On Fri, Jun 09, 2017 at 06:36:32PM +0300, Andy Shevchenko wrote:
> On Fri, Jun 9, 2017 at 1:54 PM, 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 unknown 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.
>
> Below looks better for my taste.
> See also comments.
>
Still thanks for your review.
> > +static int acpi_ost_status_code(u32 src, int error)
> > +{
> > + switch (src) {
> > + case ACPI_NOTIFY_EJECT_REQUEST:
> > + case ACPI_OST_EC_OSPM_EJECT:
>
> > + if (error == -EPERM)
> > + return ACPI_OST_SC_EJECT_NOT_SUPPORTED;
> > + else if (error == -EBUSY)
>
> Redundant else...
>
You are right, I will remove it.
> > + return ACPI_OST_SC_DEVICE_BUSY;
>
> Perhaps switch case here as well?
> switch (error) {
> case -EPERM;
> return X;
> case -EBUSY:
> return Y;
> }
>
I want to use the event source as the target of switch because
different event source has different ost_src definition. If I
add the support of insertion event then the code will be like
this:
static int acpi_ost_status_code(u32 src, int error)
{
switch (src) {
case ACPI_NOTIFY_EJECT_REQUEST:
case ACPI_OST_EC_OSPM_EJECT:
if (error == -EPERM)
return ACPI_OST_SC_EJECT_NOT_SUPPORTED;
if (error == -EBUSY)
return ACPI_OST_SC_DEVICE_BUSY;
break;
case ACPI_OST_EC_OSPM_INSERTION:
if (error == -EPERM)
return ACPI_OST_SC_INSERT_NOT_SUPPORTED;
if (error == -EBUSY)
return ACPI_OST_SC_INSERT_IN_PROGRESS;
break;
}
return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS;
}
The ACPI_OST_EC_OSPM_INSERTION represents "Insertion Processing
(Source Event: 0x200)" that it has different ost code definition.
Just we didn't support it in kernel (maybe just didn't see any
machine used it).
> > + break;
> > + }
> > + return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS;
> > +}
>
>
> > + ost_code = acpi_ost_status_code(src, error);
> > err_out:
>
> I guess you need to swap those lines.
>
Do you mean move the "err_out:" to the position before
acpi_ost_status_code()? The err_out tag used by the
validation checking of acpi handler that it wants to
jump to evaluate _OST:
void acpi_device_hotplug(struct acpi_device *adev, u32 src)
{
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
int error = -ENODEV;
lock_device_hotplug();
mutex_lock(&acpi_scan_lock);
/*
* The device object's ACPI handle cannot become invalid as long as we
* are holding acpi_scan_lock, but it might have become invalid before
* that lock was acquired.
*/
if (adev->handle == INVALID_ACPI_HANDLE)
goto err_out;
[...snip]
> > err_out:
> > acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
>
Thanks a lot!
Joey Lee