From 9cbc7960288d28aec95257af59854e1d14ba23b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89ric=20Piel?= <Eric.Piel@tremplin-utc.net>
Date: Tue, 5 Feb 2008 00:04:58 +0100
Subject: [PATCH] ACPI: Add "acpi_no_initrd_override" kernel parameter
The acpi_no_initrd_override parameter permits to disable the load of an ACPI
table from the initramfs.
Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Len Brown <len.brown@intel.com>
---
Documentation/kernel-parameters.txt | 3 +++
drivers/acpi/osl.c | 16 +++++++++++++++-
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8fd5aa40585ff..ef2316a1a731d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -175,6 +175,9 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+ acpi_no_initrd_override [KNL,ACPI]
+ Disable loading custom ACPI tables from the initramfs
+
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index bbd8360bfb233..2b41bdddbeb68 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -77,6 +77,10 @@ static struct workqueue_struct *kacpi_notify_wq;
#define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
static char osi_additional_string[OSI_STRING_LENGTH_MAX];
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static int acpi_no_initrd_override;
+#endif
+
/*
* "Ode to _OSI(Linux)"
*
@@ -386,7 +390,8 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
*new_table = (struct acpi_table_header *)AmlCode;
#endif
#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
- if (strncmp(existing_table->signature, "DSDT", 4) == 0) {
+ if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
+ !acpi_no_initrd_override) {
struct acpi_table_header *initrd_table = acpi_find_dsdt_initrd();
if (initrd_table)
*new_table = initrd_table;
@@ -402,6 +407,15 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
return AE_OK;
}
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+int __init acpi_no_initrd_override_setup(char *s)
+{
+ acpi_no_initrd_override = 1;
+ return 1;
+}
+__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
+#endif
+
static irqreturn_t acpi_irq(int irq, void *dev_id)
{
return (*acpi_irq_handler) (acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
--
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