From patchwork Tue Sep 18 23:44:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yinghai Lu X-Patchwork-Id: 1475101 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 5E3EC3FCFC for ; Tue, 18 Sep 2012 23:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752012Ab2IRXqB (ORCPT ); Tue, 18 Sep 2012 19:46:01 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:29649 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752008Ab2IRXqA (ORCPT ); Tue, 18 Sep 2012 19:46:00 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by rcsinet15.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id q8INikTp022810 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 18 Sep 2012 23:44:47 GMT Received: from acsmt357.oracle.com (acsmt357.oracle.com [141.146.40.157]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id q8INijLZ019806 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 18 Sep 2012 23:44:46 GMT Received: from abhmt110.oracle.com (abhmt110.oracle.com [141.146.116.62]) by acsmt357.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id q8INiiUw027562; Tue, 18 Sep 2012 18:44:44 -0500 Received: from linux-siqj.site (/10.132.126.191) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 18 Sep 2012 16:44:44 -0700 From: Yinghai Lu To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yinghai Lu , x86@kernel.org, Dave Airlie , Andrew Morton , Julia Lawall , Matthew Garrett Subject: [PATCH] PCI: fix default vga ref_count Date: Tue, 18 Sep 2012 16:44:42 -0700 Message-Id: <1348011882-31452-1-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: References: X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org when __ARCH_HAS_VGA_DEFAULT_DEVICE is not defined, aka EFIFB is not used, for static path, vga_default setting is through vga_arbiter_add_pci_device. and later x86 pci_fixup_video, will skip setting again. - subsys_initcall(vga_arb_device_init) come first to call vga_arbiter_add_pci_device. It will call pci_get_dev to hold one reference. for hotplug add path, even vga_arbiter_add_pci_device is called via notifier, but it will check VGA_RSRC_LEGACY_MASK that is not set for hotplug path. So x86 pci_fixup_video will take over to call vga_set_default_device(). It will not hold one refrence. Later for hotplug remove path, vga_arbiter_del_pci_device that does not check VGA_RSRC_LEGACY_MASK will call put_device and it will cause ref_count to decrease extra. that will have that pci device get deleted early wrongly. Need to make get/put balance for both cases. -v2: According to Bjorn, update vga_set_default_device instead... Signed-off-by: Yinghai Lu Cc: x86@kernel.org Cc: Dave Airlie Cc: Andrew Morton Cc: Julia Lawall Cc: Matthew Garrett --- drivers/gpu/vga/vgaarb.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/drivers/gpu/vga/vgaarb.c =================================================================== --- linux-2.6.orig/drivers/gpu/vga/vgaarb.c +++ linux-2.6/drivers/gpu/vga/vgaarb.c @@ -141,6 +141,12 @@ EXPORT_SYMBOL_GPL(vga_default_device); void vga_set_default_device(struct pci_dev *pdev) { + if (vga_default) + pci_dev_put(vga_default); + + if (pdev) + pdev = pci_dev_get(pdev); + vga_default = pdev; } #endif @@ -577,7 +583,7 @@ static bool vga_arbiter_add_pci_device(s #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE if (vga_default == NULL && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) - vga_default = pci_dev_get(pdev); + vga_set_default_device(pdev); #endif vga_arbiter_check_bridge_sharing(vgadev); @@ -613,10 +619,8 @@ static bool vga_arbiter_del_pci_device(s } #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE - if (vga_default == pdev) { - pci_dev_put(vga_default); - vga_default = NULL; - } + if (vga_default == pdev) + vga_set_default_device(NULL); #endif if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))