From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932556AbaCEO4x (ORCPT ); Wed, 5 Mar 2014 09:56:53 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41576 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755506AbaCEOh3 (ORCPT ); Wed, 5 Mar 2014 09:37:29 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Bjorn Helgaas , Sarah Sharp , Luis Henriques Subject: [PATCH 3.5 12/62] PCI: Enable INTx if BIOS left them disabled Date: Wed, 5 Mar 2014 14:36:16 +0000 Message-Id: <1394030226-26652-13-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1394030226-26652-1-git-send-email-luis.henriques@canonical.com> References: <1394030226-26652-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.32 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Bjorn Helgaas commit 1f42db786b14a31bf807fc41ee5583a00c08fcb1 upstream. Some firmware leaves the Interrupt Disable bit set even if the device uses INTx interrupts. Clear Interrupt Disable so we get those interrupts. Based on the report mentioned below, if the user selects the "EHCI only" option in the Intel Baytrail BIOS, the EHCI device is handed off to the OS with the PCI_COMMAND_INTX_DISABLE bit set. Link: http://lkml.kernel.org/r/20140114181721.GC12126@xanatos Link: https://bugzilla.kernel.org/show_bug.cgi?id=70601 Reported-by: Chris Cheng Reported-and-tested-by: Jamie Chen Signed-off-by: Bjorn Helgaas CC: Sarah Sharp Signed-off-by: Luis Henriques --- drivers/pci/pci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index caeddd4..42b9983 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1134,6 +1134,8 @@ EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; + u16 cmd; + u8 pin; err = pci_set_power_state(dev, PCI_D0); if (err < 0 && err != -EIO) @@ -1143,6 +1145,14 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars) return err; pci_fixup_device(pci_fixup_enable, dev); + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); + if (pin) { + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_INTX_DISABLE) + pci_write_config_word(dev, PCI_COMMAND, + cmd & ~PCI_COMMAND_INTX_DISABLE); + } + return 0; } -- 1.9.0