Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir@xen.org>
# Date 1292409068 0
# Node ID 612eb10ba78b5ca72ca9c26fb68f1e003bdba34a
# Parent 13c7c6fade3667279b5ff197ebed90874e328bee
x86 acpi: Follow Windows behaviour more closely during reset.

This follows some changes proposed for upstream Linux:
1. Do not check the FADT reset register size/offset
2. Try ACPI poking twice during our reset attempt sequence

Hopefully this will help us reset reliably on a wider range of
platforms.

Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset: 22482:91e0556f4d46
xen-unstable date: Fri Dec 10 11:32:19 2010 +0000

x86: acpi: Fix reboot attempt sequence.

Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset: 22483:901c118b363e
xen-unstable date: Fri Dec 10 16:40:05 2010 +0000
---
xen/arch/x86/shutdown.c | 21 ++++++++++++++++-----
xen/drivers/acpi/reboot.c | 7 ++++---
2 files changed, 20 insertions(+), 8 deletions(-)

diff -r 13c7c6fade36 -r 612eb10ba78b xen/arch/x86/shutdown.c
--- a/xen/arch/x86/shutdown.c Fri Dec 10 11:39:01 2010 +0000
+++ b/xen/arch/x86/shutdown.c Wed Dec 15 10:31:08 2010 +0000
@@ -301,7 +301,8 @@ static void __machine_restart(void *pdel

void machine_restart(unsigned int delay_millisecs)
{
- int i;
+ unsigned int i, attempt;
+ enum reboot_type orig_reboot_type = reboot_type;

watchdog_disable();
console_start_sync();
@@ -336,7 +337,7 @@ void machine_restart(unsigned int delay_
/* Rebooting needs to touch the page at absolute address 0. */
*((unsigned short *)__va(0x472)) = reboot_mode;

- for ( ; ; )
+ for ( attempt = 0; ; attempt++ )
{
switch ( reboot_type )
{
@@ -349,19 +350,29 @@ void machine_restart(unsigned int delay_
outb(0xfe,0x64); /* pulse reset low */
udelay(50);
}
- /* fall through */
+ /*
+ * If this platform supports ACPI reset, we follow a Windows-style
+ * reboot attempt sequence:
+ * ACPI -> KBD -> ACPI -> KBD
+ * After this we revert to our usual sequence:
+ * KBD -> TRIPLE -> KBD -> TRIPLE -> KBD -> ...
+ */
+ reboot_type = (((attempt == 1) && (orig_reboot_type == BOOT_ACPI))
+ ? BOOT_ACPI : BOOT_TRIPLE);
+ break;
case BOOT_TRIPLE:
asm volatile ( "lidt %0 ; int3" : "=m" (no_idt) );
+ reboot_type = BOOT_KBD;
break;
case BOOT_BIOS:
machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
+ reboot_type = BOOT_KBD;
break;
case BOOT_ACPI:
acpi_reboot();
+ reboot_type = BOOT_KBD;
break;
}
-
- reboot_type = BOOT_KBD;
}
}

diff -r 13c7c6fade36 -r 612eb10ba78b xen/drivers/acpi/reboot.c
--- a/xen/drivers/acpi/reboot.c Fri Dec 10 11:39:01 2010 +0000
+++ b/xen/drivers/acpi/reboot.c Wed Dec 15 10:31:08 2010 +0000
@@ -10,9 +10,10 @@ void acpi_reboot(void)

rr = &acpi_gbl_FADT.reset_register;

- /* Is the reset register supported? */
- if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER) ||
- (rr->bit_width != 8) || (rr->bit_offset != 0))
+ /* Is the reset register supported? The spec says we should be
+ * checking the bit width and bit offset, but Windows ignores
+ * these fields */
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER))
return;

reset_value = acpi_gbl_FADT.reset_value;

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