From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932093AbbDMK4Y (ORCPT ); Mon, 13 Apr 2015 06:56:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59123 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753923AbbDMK4T (ORCPT ); Mon, 13 Apr 2015 06:56:19 -0400 From: Vitaly Kuznetsov To: "K. Y. Srinivasan" Cc: Haiyang Zhang , devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, Dexuan Cui , Jake Oshins , Nick Meier Subject: [PATCH 1/2] Drivers: hv: vmbus: introduce vmbus_acpi_remove Date: Mon, 13 Apr 2015 12:56:06 +0200 Message-Id: <1428922567-11225-2-git-send-email-vkuznets@redhat.com> In-Reply-To: <1428922567-11225-1-git-send-email-vkuznets@redhat.com> References: <1428922567-11225-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case we do request_resource() in vmbus_acpi_add() we need to tear it down to be able to load the driver again. Otherwise the following crash in observed when hv_vmbus unload/load sequence is performed on a Generation2 instance: [ 38.165701] BUG: unable to handle kernel paging request at ffffffffa00075a0 [ 38.166315] IP: [] __request_resource+0x2f/0x50 [ 38.166315] PGD 1f34067 PUD 1f35063 PMD 3f723067 PTE 0 [ 38.166315] Oops: 0000 [#1] SMP [ 38.166315] Modules linked in: hv_vmbus(+) [last unloaded: hv_vmbus] [ 38.166315] CPU: 0 PID: 267 Comm: modprobe Not tainted 3.19.0-rc5_bug923184+ #486 [ 38.166315] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 38.166315] task: ffff88003f401cb0 ti: ffff88003f60c000 task.ti: ffff88003f60c000 [ 38.166315] RIP: 0010:[] [] __request_resource+0x2f/0x50 [ 38.166315] RSP: 0018:ffff88003f60fb58 EFLAGS: 00010286 ... Signed-off-by: Vitaly Kuznetsov --- drivers/hv/vmbus_drv.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index c85235e..0d8d1d7 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1035,6 +1035,15 @@ acpi_walk_err: return ret_val; } +static int vmbus_acpi_remove(struct acpi_device *device) +{ + int ret = 0; + + if (hyperv_mmio.start && hyperv_mmio.end) + ret = release_resource(&hyperv_mmio); + return ret; +} + static const struct acpi_device_id vmbus_acpi_device_ids[] = { {"VMBUS", 0}, {"VMBus", 0}, @@ -1047,6 +1056,7 @@ static struct acpi_driver vmbus_acpi_driver = { .ids = vmbus_acpi_device_ids, .ops = { .add = vmbus_acpi_add, + .remove = vmbus_acpi_remove, }, }; -- 1.9.3