Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754522AbdGCN0Q (ORCPT ); Mon, 3 Jul 2017 09:26:16 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:34722 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754089AbdGCN0O (ORCPT ); Mon, 3 Jul 2017 09:26:14 -0400 From: "Lee, Chun-Yi" X-Google-Original-From: "Lee, Chun-Yi" To: "Rafael J . Wysocki" Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, "Lee, Chun-Yi" , Len Brown , Andy Shevchenko , Michal Hocko Subject: [RFC PATCH v4] acpi: indicate to platform when hot remove returns busy Date: Mon, 3 Jul 2017 21:26:10 +0800 Message-Id: <20170703132610.21719-1-jlee@suse.com> X-Mailer: git-send-email 2.12.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2844 Lines: 86 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" Cc: Len Brown Cc: Andy Shevchenko Cc: Michal Hocko Signed-off-by: "Lee, Chun-Yi" --- 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