From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp07.au.ibm.com ([202.81.31.140]:37022 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758822AbaLKGEQ (ORCPT ); Thu, 11 Dec 2014 01:04:16 -0500 Received: from /spool/local by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 11 Dec 2014 16:04:14 +1000 Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 969B42BB0057 for ; Thu, 11 Dec 2014 17:04:10 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sBB642D737486592 for ; Thu, 11 Dec 2014 17:04:10 +1100 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sBB63bKl012945 for ; Thu, 11 Dec 2014 17:03:38 +1100 From: Gavin Shan To: linux-pci@vger.kernel.org Cc: bhelgaas@google.com, rjw@sisk.pl, Gavin Shan Subject: [PATCH RFC] PCI: Turn off BARs when disabling device Date: Thu, 11 Dec 2014 17:03:12 +1100 Message-Id: <1418277792-4090-1-git-send-email-gwshan@linux.vnet.ibm.com> Sender: linux-pci-owner@vger.kernel.org List-ID: When unbinding PCI device mlx4 from its driver, the PCI device is disabled by pci_disable_device() and the BARs (IO and memory) should be disabled at the point. However, the memory BARs are still active after the mlx4_core driver is unloaded as following logs show. # lspci -vv -s 0003:0f:00.0 0003:0f:00.0 Network controller: Mellanox Technologies \ MT27500 Family [ConnectX-3] Subsystem: Mellanox Technologies Device 0061 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- \ ParErr+ Stepping- SERR+ FastB2B- DisINTx+ : Kernel driver in use: mlx4_core # echo 0003:0f:00.0 > /sys/bus/pci/drivers/mlx4_core/unbind # lspci -vv -s 0003:0f:00.0 0003:0f:00.0 Network controller: Mellanox Technologies \ MT27500 Family [ConnectX-3] Subsystem: Mellanox Technologies Device 0061 Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- \ ParErr+ Stepping- SERR+ FastB2B- DisINTx- The patch turns off all BARs (IO and memory) in do_pci_disable_device(). Signed-off-by: Gavin Shan --- drivers/pci/pci.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 625a4ac..8d2924b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1496,12 +1496,14 @@ void __weak pcibios_penalize_isa_irq(int irq, int active) {} static void do_pci_disable_device(struct pci_dev *dev) { - u16 pci_command; + u16 cmd, flags = (PCI_COMMAND_IO | + PCI_COMMAND_MEMORY | + PCI_COMMAND_MASTER); - pci_read_config_word(dev, PCI_COMMAND, &pci_command); - if (pci_command & PCI_COMMAND_MASTER) { - pci_command &= ~PCI_COMMAND_MASTER; - pci_write_config_word(dev, PCI_COMMAND, pci_command); + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & flags) { + cmd &= ~flags; + pci_write_config_word(dev, PCI_COMMAND, cmd); } pcibios_disable_device(dev); -- 1.8.3.2