Subject: ACPI: introduce boot option acpi=rsdt_forced
From: Zhao Yakui  <[EMAIL PROTECTED]>

Maybe XSDT has NULL entry address. When it is found that
XSDT has NULL entry address, the promote info is given to user
(XSDT has NULL entry address, please try to boot with "acpi=rsdt_forced").
The system had better be booted with acpi=rsdt_forced option

http://bugzilla.kernel.org/show_bug.cgi?id=8630

Signed-off-by: Zhao Yakui  <[EMAIL PROTECTED]>

---
 Documentation/kernel-parameters.txt |    1 +
 arch/i386/kernel/acpi/boot.c        |    4 ++++
 drivers/acpi/tables/tbutils.c       |   13 ++++++++++---
 include/acpi/acglobal.h             |    2 ++
 4 files changed, 17 insertions(+), 3 deletions(-)

Index: linux-2.6.23-rc3/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.23-rc3.orig/Documentation/kernel-parameters.txt
+++ linux-2.6.23-rc3/Documentation/kernel-parameters.txt
@@ -132,6 +132,7 @@ and is between 256 and 4096 characters. 
                        ht -- run only enough ACPI to enable Hyper Threading
                        strict -- Be less tolerant of platforms that are not
                                strictly ACPI specification compliant.
+                       rsdt_forced -- force to use RSDT table
 
                        See also Documentation/pm.txt, pci=noacpi
 
Index: linux-2.6.23-rc3/arch/i386/kernel/acpi/boot.c
===================================================================
--- linux-2.6.23-rc3.orig/arch/i386/kernel/acpi/boot.c
+++ linux-2.6.23-rc3/arch/i386/kernel/acpi/boot.c
@@ -1248,6 +1248,10 @@ static int __init parse_acpi(char *arg)
        /* "acpi=noirq" disables ACPI interrupt routing */
        else if (strcmp(arg, "noirq") == 0) {
                acpi_noirq_set();
+       }
+       /* "acpi=rsdt_forced" force to use RSDT */
+       else if (strcmp(arg, "rsdt_forced") == 0) {
+               rsdt_forced = 1;
        } else {
                /* Core will printk when we return error. */
                return -EINVAL;
Index: linux-2.6.23-rc3/drivers/acpi/tables/tbutils.c
===================================================================
--- linux-2.6.23-rc3.orig/drivers/acpi/tables/tbutils.c
+++ linux-2.6.23-rc3/drivers/acpi/tables/tbutils.c
@@ -47,6 +47,7 @@
 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbutils")
 
+u32 rsdt_forced ;
 /* Local prototypes */
 static acpi_physical_address
 acpi_tb_get_root_table_entry(u8 * table_entry,
@@ -341,6 +342,7 @@ acpi_tb_parse_root_table(acpi_physical_a
        u32 table_count;
        struct acpi_table_header *table;
        acpi_physical_address address;
+       acpi_physical_address entry_address;
        u32 length;
        u8 *table_entry;
        acpi_status status;
@@ -361,7 +363,8 @@ acpi_tb_parse_root_table(acpi_physical_a
 
        /* Differentiate between RSDT and XSDT root tables */
 
-       if (rsdp->revision > 1 && rsdp->xsdt_physical_address) {
+       if (rsdp->revision > 1 && rsdp->xsdt_physical_address
+               && !rsdt_forced) {
                /*
                 * Root table is an XSDT (64-bit physical addresses). We must 
use the
                 * XSDT if the revision is > 1 and the XSDT pointer is present, 
as per
@@ -455,11 +458,15 @@ acpi_tb_parse_root_table(acpi_physical_a
                acpi_gbl_root_table_list.tables[acpi_gbl_root_table_list.count].
                    address =
                    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
-
+               entry_address =
+                   acpi_tb_get_root_table_entry(table_entry, table_entry_size);
+               if (!entry_address && table_entry_size == sizeof(u64) ) {
+                       ACPI_WARNING((AE_INFO, "XSDT has NULL entry. "
+                       "Please try to boot with \"acpi=rsdt_forced\""));
+               }
                table_entry += table_entry_size;
                acpi_gbl_root_table_list.count++;
        }
-
        /*
         * It is not possible to map more than one entry in some environments,
         * so unmap the root table here before mapping other tables
Index: linux-2.6.23-rc3/include/acpi/acglobal.h
===================================================================
--- linux-2.6.23-rc3.orig/include/acpi/acglobal.h
+++ linux-2.6.23-rc3/include/acpi/acglobal.h
@@ -117,6 +117,8 @@ extern u32 acpi_dbg_layer;
 
 extern u32 acpi_gbl_nesting_level;
 
+extern u32 rsdt_forced;
+
 /* Event counters */
 
 ACPI_EXTERN u32 acpi_gpe_count;
-
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to