Messages in this thread Patch in this message | | | From | "Lee, Chun-Yi" <> | Subject | [RFC PATCH v4] acpi: indicate to platform when hot remove returns busy | Date | Fri, 7 Jul 2017 14:25:23 +0800 |
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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(-)
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); -- 2.10.2
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