Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751558AbdFGGHo (ORCPT ); Wed, 7 Jun 2017 02:07:44 -0400 Received: from mail-pg0-f68.google.com ([74.125.83.68]:34138 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750831AbdFGGHj (ORCPT ); Wed, 7 Jun 2017 02:07:39 -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 Subject: [RFC PATCH] acpi: indicate to platform when hot remove returns busy Date: Wed, 7 Jun 2017 14:07:27 +0800 Message-Id: <20170607060727.23712-1-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: 2861 Lines: 77 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" Cc: Len Brown Signed-off-by: "Lee, Chun-Yi" --- 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