From 14bdd0d36f5284108468bb73afd50726b07c7a84 Mon Sep 17 00:00:00 2001

From: Kyle McMartin <kyle@phobos.i.jkkm.org>

Date: Mon, 29 Mar 2010 23:43:49 -0400

Subject: linux-2.6-defaults-pci_no_msi

---

 Documentation/kernel-parameters.txt |    3 +++

 drivers/pci/Kconfig                 |   12 ++++++++++++

 drivers/pci/msi.c                   |    9 +++++++++

 drivers/pci/pci.c                   |    2 ++

 drivers/pci/pci.h                   |    2 ++

 5 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt

index e4cbca5..8154a0f 100644

--- a/Documentation/kernel-parameters.txt

+++ b/Documentation/kernel-parameters.txt

@@ -1911,6 +1911,9 @@ and is between 256 and 4096 characters. It is defined in the file

 		check_enable_amd_mmconf [X86] check for and enable

 				properly configured MMIO access to PCI

 				config space on AMD family 10h CPU

+		msi		[MSI] If the PCI_MSI kernel config parameter is

+				enabled, this kernel boot option can be used to

+				enable the use of MSI interrupts system-wide.

 		nomsi		[MSI] If the PCI_MSI kernel config parameter is

 				enabled, this kernel boot option can be used to

 				disable the use of MSI interrupts system-wide.

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig

index 7858a11..b12fcad 100644

--- a/drivers/pci/Kconfig

+++ b/drivers/pci/Kconfig

@@ -21,6 +21,18 @@ config PCI_MSI

 	   If you don't know what to do here, say Y.

+config PCI_MSI_DEFAULT_ON

+	def_bool y

+	prompt "Use Message Signaled Interrupts by default"

+	depends on PCI_MSI

+	help

+	  Selecting this option will enable use of PCI MSI where applicable

+	  by default. Support for MSI can be disabled through the use of the

+	  pci=nomsi boot flag. Conversely, if this option is not selected,

+	  support for PCI MSI can be enabled by passing the pci=msi flag.

+

+	  If you don't know what to do here, say N.

+

 config PCI_DEBUG

 	bool "PCI Debugging"

 	depends on PCI && DEBUG_KERNEL

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c

index f9cf317..6b0539a 100644

--- a/drivers/pci/msi.c

+++ b/drivers/pci/msi.c

@@ -22,7 +22,11 @@

 #include "pci.h"

 #include "msi.h"

+#ifdef CONFIG_PCI_MSI_DEFAULT_ON

 static int pci_msi_enable = 1;

+#else

+static int pci_msi_enable = 0;

+#endif /*CONFIG_PCI_MSI_DEFAULT_ON*/

 /* Arch hooks */

@@ -836,6 +840,11 @@ int pci_msi_enabled(void)

 }

 EXPORT_SYMBOL(pci_msi_enabled);

+void pci_yes_msi(void)

+{

+	pci_msi_enable = 1;

+}

+

 void pci_msi_init_pci_dev(struct pci_dev *dev)

 {

 	INIT_LIST_HEAD(&dev->msi_list);

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c

index 1531f3a..3cb332b 100644

--- a/drivers/pci/pci.c

+++ b/drivers/pci/pci.c

@@ -2983,6 +2983,8 @@ static int __init pci_setup(char *str)

 		if (*str && (str = pcibios_setup(str)) && *str) {

 			if (!strcmp(str, "nomsi")) {

 				pci_no_msi();

+			} else if (!strcmp(str, "msi")) {

+				pci_yes_msi();

 			} else if (!strcmp(str, "noaer")) {

 				pci_no_aer();

 			} else if (!strcmp(str, "nodomains")) {

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h

index 4eb10f4..caa051e 100644

--- a/drivers/pci/pci.h

+++ b/drivers/pci/pci.h

@@ -122,9 +122,11 @@ extern unsigned int pci_pm_d3_delay;

 #ifdef CONFIG_PCI_MSI

 void pci_no_msi(void);

+void pci_yes_msi(void);

 extern void pci_msi_init_pci_dev(struct pci_dev *dev);

 #else

 static inline void pci_no_msi(void) { }

+static inline void pci_yes_msi(void) { }

 static inline void pci_msi_init_pci_dev(struct pci_dev *dev) { }

 #endif

-- 

1.7.0.1