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[3.11.y.z,extended,stable] Patch "PCI: Enable INTx if BIOS left them disabled" has been added to staging queue

Message ID 1393417357-29445-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Feb. 26, 2014, 12:22 p.m. UTC 
This is a note to let you know that I have just added a patch titled

    PCI: Enable INTx if BIOS left them disabled

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 8ab8f1ff0fbe726d93f9c57368e857a5f2b9c868 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 14 Feb 2014 13:48:16 -0700
Subject: PCI: Enable INTx if BIOS left them disabled

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 <chris.cheng@atrustcorp.com>
Reported-and-tested-by: Jamie Chen <jamie.chen@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/pci/pci.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

--
1.9.0
diff mbox

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e37fea6..1088e0d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1119,6 +1119,8 @@  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)
@@ -1128,6 +1130,14 @@  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;
 }