acpi=off and acpi_get_firmware_table

[Corey Minyard]

In 2.6.12-rc4, I added acpi=off to the kernel command line and it 
panic-ed in acpi_get_firmware_table, called from the IPMI driver.

The attached patch fixes the problem, but it still spits out ugly 
"ACPI-0166: *** Error: Invalid address flags 8" errors.  So I doubt the 
patch is right, but maybe it points to something else.

Is it legal to call acpi_get_firmware_table if acpi is off?  If not, how 
can I tell that acpi is off?

-Corey
Index: linux-2.6.12-rc4/drivers/acpi/tables/tbxfroot.c
===================================================================
--- linux-2.6.12-rc4.orig/drivers/acpi/tables/tbxfroot.c
+++ linux-2.6.12-rc4/drivers/acpi/tables/tbxfroot.c
@@ -313,7 +313,9 @@
 
 
 cleanup:
-	acpi_os_unmap_memory (rsdt_info->pointer, (acpi_size) rsdt_info->pointer->length);
+	if (rsdt_info->pointer)
+		acpi_os_unmap_memory (rsdt_info->pointer,
+			       	      (acpi_size) rsdt_info->pointer->length);
 	ACPI_MEM_FREE (rsdt_info);
 
 	if (header) {