[PATCH 5/7] Allow disabling legacy power management modes with paravirt kernels

Chris Wright
2006-10-29T02:46:52Z

[-- Attachment #1: 016-power-management-bypass.patch --]
[-- Type: text/plain, Size: 1552 bytes --]

Two legacy power management modes are much easier to just explicitly disable
when running in paravirtualized mode - neither APM nor PnP is still relevant.
The status of ACPI is still debatable, and noacpi is still a common enough
boot parameter that it is not necessary to explicitly disable ACPI.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

---
arch/i386/kernel/apm.c | 3 ++-
drivers/pnp/pnpbios/core.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)

--- linux-2.6-pv.orig/arch/i386/kernel/apm.c
+++ linux-2.6-pv/arch/i386/kernel/apm.c
@@ -231,6 +231,7 @@
#include <asm/uaccess.h>
#include <asm/desc.h>
#include <asm/i8253.h>
+#include <asm/paravirt.h>

#include "io_ports.h"

@@ -2191,7 +2192,7 @@ static int __init apm_init(void)

dmi_check_system(apm_dmi_table);

- if (apm_info.bios.version == 0) {
+ if (apm_info.bios.version == 0 || paravirt_enabled()) {
printk(KERN_INFO "apm: BIOS not found.\n");
return -ENODEV;
}
--- linux-2.6-pv.orig/drivers/pnp/pnpbios/core.c
+++ linux-2.6-pv/drivers/pnp/pnpbios/core.c
@@ -530,7 +530,8 @@ static int __init pnpbios_init(void)
if (check_legacy_ioport(PNPBIOS_BASE))
return -ENODEV;
#endif
- if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table)) {
+ if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
+ paravirt_enabled()) {
printk(KERN_INFO "PnPBIOS: Disabled\n");
return -ENODEV;
}

--