[PATCH] ACPI: use MSI_NOT_SUPPORTED bit

From: Randy Dunlap
Date: Wed Nov 15 2006 - 13:41:02 EST


On 15 Nov 2006 05:49:41 +0100 Andi Kleen wrote:

> BTW there seems to be a new ACPI FADT bit that says "MSI is broken"
> We should probably check that too as a double check.

Do you mean more than just use that bit when you say "double check"?

I wonder why this hasn't already been done. (?)

How's this look? Build-tested only.

---
From: Randy Dunlap <randy.dunlap@xxxxxxxxxx>

Implement use of FADT boot_flags.MSI_NOT_SUPPORTED bit to prevent
assigning MSIs.
Force MSI_NOT_SUPPORTED for ACPI 1.0 tables.

Signed-off-by: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
---
drivers/acpi/bus.c | 6 ++++++
drivers/acpi/tables/tbconvrt.c | 3 ++-
include/acpi/actbl.h | 4 +++-
include/linux/pci.h | 2 ++
4 files changed, 13 insertions(+), 2 deletions(-)

--- linux-2619-rc5.orig/include/acpi/actbl.h
+++ linux-2619-rc5/include/acpi/actbl.h
@@ -290,7 +290,7 @@ struct fadt_descriptor_rev1 {
ACPI_FADT_COMMON u32 flags;
};

-/* FADT: Prefered Power Management Profiles */
+/* FADT: Preferred Power Management Profiles */

#define PM_UNSPECIFIED 0
#define PM_DESKTOP 1
@@ -304,6 +304,8 @@ struct fadt_descriptor_rev1 {

#define BAF_LEGACY_DEVICES 0x0001
#define BAF_8042_KEYBOARD_CONTROLLER 0x0002
+#define BAF_VGA_NOT_PRESENT 0x0004
+#define BAF_MSI_NOT_SUPPORTED 0x0008

#define FADT2_REVISION_ID 3
#define FADT2_MINUS_REVISION_ID 2
--- linux-2619-rc5.orig/drivers/acpi/tables/tbconvrt.c
+++ linux-2619-rc5/drivers/acpi/tables/tbconvrt.c
@@ -289,7 +289,8 @@ acpi_tb_convert_fadt1(struct fadt_descri
* Since there isn't any equivalence in 1.0 and since it is highly
* likely that a 1.0 system has legacy support.
*/
- local_fadt->iapc_boot_arch = BAF_LEGACY_DEVICES;
+ local_fadt->iapc_boot_arch = BAF_LEGACY_DEVICES |
+ BAF_MSI_NOT_SUPPORTED;
}

/*
--- linux-2619-rc5.orig/include/linux/pci.h
+++ linux-2619-rc5/include/linux/pci.h
@@ -610,6 +610,7 @@ static inline int pci_enable_msix(struct
struct msix_entry *entries, int nvec) {return -1;}
static inline void pci_disable_msix(struct pci_dev *dev) {}
static inline void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
+static inline void pci_no_msi(void) {}
#else
extern void pci_scan_msi_device(struct pci_dev *dev);
extern int pci_enable_msi(struct pci_dev *dev);
@@ -618,6 +619,7 @@ extern int pci_enable_msix(struct pci_de
struct msix_entry *entries, int nvec);
extern void pci_disable_msix(struct pci_dev *dev);
extern void msi_remove_pci_irq_vectors(struct pci_dev *dev);
+extern void pci_no_msi(void);
#endif

#ifdef CONFIG_HT_IRQ
--- linux-2619-rc5.orig/drivers/acpi/bus.c
+++ linux-2619-rc5/drivers/acpi/bus.c
@@ -28,6 +28,7 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
+#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/pm_legacy.h>
#include <linux/device.h>
@@ -637,6 +638,11 @@ void __init acpi_early_init(void)
}
#endif

+ if (acpi_fadt.iapc_boot_arch & BAF_MSI_NOT_SUPPORTED) {
+ printk(KERN_DEBUG PREFIX "MSI not supported, disabling it\n");
+ pci_no_msi();
+ }
+
status =
acpi_enable_subsystem(~
(ACPI_NO_HARDWARE_INIT |
-
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