diff mbox

[RFC,v4] acpi: indicate to platform when hot remove returns busy

Message ID 20170707062523.29735-1-jlee@suse.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Chun-Yi Lee July 7, 2017, 6:25 a.m. UTC
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.

v4:
Use switch-case statements to simplify code. (Andy Shevchenko, Rafael J. Wysocki)

v3:
Removed redundant 'else' in acpi_ost_status_code(). (Andy Shevchenko)

v2:
Do not overwrite ost code in acpi_generic_hotplug_event(). Move
the "error code to ost code" logic to a help function. (Andy Shevchenko)

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
---
 drivers/acpi/scan.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

Comments

Rafael J. Wysocki July 7, 2017, 1:16 p.m. UTC | #1
On Friday, July 07, 2017 02:25:23 PM Lee, Chun-Yi 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.
> 
> v4:
> Use switch-case statements to simplify code. (Andy Shevchenko, Rafael J. Wysocki)
> 
> v3:
> Removed redundant 'else' in acpi_ost_status_code(). (Andy Shevchenko)
> 
> v2:
> Do not overwrite ost code in acpi_generic_hotplug_event(). Move
> the "error code to ost code" logic to a help function. (Andy Shevchenko)
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Len Brown <lenb@kernel.org>
> Cc: Michal Hocko <mhocko@suse.cz>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>

I've applied this one already I think.

Please check in linux-next.

> ---
>  drivers/acpi/scan.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index d531629..ce88175 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -404,10 +404,6 @@ 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);
>  
> @@ -423,8 +419,20 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src)
>  		else
>  			goto out;
>  	}
> -	if (!error)
> +	switch (error) {
> +	case 0:
>  		ost_code = ACPI_OST_SC_SUCCESS;
> +		break;
> +	case -EPERM:
> +		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
> +		break;
> +	case -EBUSY:
> +		ost_code = ACPI_OST_SC_DEVICE_BUSY;
> +		break;
> +	default:
> +		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
> +		break;
> +	}
>  
>   err_out:
>  	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
> 

--
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 mbox

Patch

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index d531629..ce88175 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -404,10 +404,6 @@  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);
 
@@ -423,8 +419,20 @@  void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 		else
 			goto out;
 	}
-	if (!error)
+	switch (error) {
+	case 0:
 		ost_code = ACPI_OST_SC_SUCCESS;
+		break;
+	case -EPERM:
+		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
+		break;
+	case -EBUSY:
+		ost_code = ACPI_OST_SC_DEVICE_BUSY;
+		break;
+	default:
+		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+		break;
+	}
 
  err_out:
 	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);