Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753225AbdDCPzn (ORCPT ); Mon, 3 Apr 2017 11:55:43 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:36129 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbdDCPzl (ORCPT ); Mon, 3 Apr 2017 11:55:41 -0400 From: "Lee, Chun-Yi" X-Google-Original-From: "Lee, Chun-Yi" To: "Rafael J . Wysocki" , Len Brown Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, "Lee, Chun-Yi" , Michal Hocko , Jiri Kosina Subject: [PATCH] ACPI: emits change uevents to all physical companion devices of container's children Date: Mon, 3 Apr 2017 23:55:33 +0800 Message-Id: <20170403155533.30283-1-jlee@suse.com> X-Mailer: git-send-email 2.10.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2718 Lines: 73 The caa73ea1 patch, "ACPI / hotplug / driver core: Handle containers in a special way", introduced the offline callback of acpi container. In the patch description, it mentions: For ACPI containers that callback simply walks the list of ACPI device objects right below the container object (its children) and checks if all of their physical companion devices are offline. If that's not the case, it returns -EBUSY and the container system devivce cannot be put offline. Consequently, to put the container system device offline, it is necessary to put all of the physical devices depending on its ACPI companion object offline beforehand. Looks that it means acpi_container_offline() should walks all physical companion devices of container's children and checks their offline state. And, the comment in source code is "Check all of the dependent devices' physical companions", which means it should checks _all_ physical companions. But, the checking code just stops at the first not-offlined physical companion device of the first not-offlined child, then kernel only emits KOBJ_CHANGE uevent to the one device. It doesn't really walk all children's all physical companion devices and doesn't send change uevent to them. This causes that usespace can only receive one uevent for one physical companion device in acpi container when acpi container offline is triggered. Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Michal Hocko Cc: Jiri Kosina Signed-off-by: "Lee, Chun-Yi" --- drivers/acpi/container.c | 5 +++-- drivers/acpi/scan.c | 1 - 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c index 12c2409..1f1537d 100644 --- a/drivers/acpi/container.c +++ b/drivers/acpi/container.c @@ -43,13 +43,14 @@ static int acpi_container_offline(struct container_dev *cdev) { struct acpi_device *adev = ACPI_COMPANION(&cdev->dev); struct acpi_device *child; + int ret = 0; /* Check all of the dependent devices' physical companions. */ list_for_each_entry(child, &adev->children, node) if (!acpi_scan_is_offline(child, false)) - return -EBUSY; + ret = -EBUSY; - return 0; + return ret; } static void acpi_container_release(struct device *dev) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 1926918..1a9055c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -134,7 +134,6 @@ bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent) kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE); offline = false; - break; } mutex_unlock(&adev->physical_node_lock); -- 2.10.2