From 2203d6ed448ff3b777ee6bb614a53e686b483e5b Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@g5.osdl.org>
Date: Fri, 18 Nov 2005 07:29:51 -0800
Subject: [PATCH] Fix ACPI processor power block initialization
Properly clear the memory, and set "pr->flags.power" only if a C2 or
deeper state is valid (to make the code match both the comment and
previous behaviour).
This fixes a boot-time lockup reported by Maneesh Soni when using
"maxcpus=1".
Acked-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
drivers/acpi/processor_idle.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 573b6a97bb1f..70d8a6ec0920 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -514,8 +514,6 @@ static int acpi_processor_set_power_policy(struct acpi_processor *pr)
static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
{
- int i;
-
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
if (!pr)
@@ -524,8 +522,7 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
if (!pr->pblk)
return_VALUE(-ENODEV);
- for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+ memset(pr->power.states, 0, sizeof(pr->power.states));
/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
@@ -555,13 +552,9 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
{
- int i;
-
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
- for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(&(pr->power.states[i]), 0,
- sizeof(struct acpi_processor_cx));
+ memset(pr->power.states, 0, sizeof(pr->power.states));
/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
@@ -873,7 +866,8 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
if (pr->power.states[i].valid) {
pr->power.count = i;
- pr->flags.power = 1;
+ if (pr->power.states[i].type >= ACPI_STATE_C2)
+ pr->flags.power = 1;
}
}
--
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