On Sun, 17 Aug 2008, David Fries wrote:
arch/x86/power/cpu_32.c __save_processor_state calls read_cr4()[...]
only a i486 CPU doesn't have the CR4 register. Trying to read it
produces an invalid opcode oops during suspend to disk.
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 81e5ab6..bd0f2a3 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -86,7 +86,9 @@ int acpi_save_state_mem(void)
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
- header->pmode_cr4 = read_cr4();
+ /* cr4 was introduced in the Pentium CPU */
+ if (boot_cpu_data.x86 >= 5)
+ header->pmode_cr4 = read_cr4();
header->realmode_flags = acpi_realmode_flags;
header->real_magic = 0x12345678;
NACK. Later i486 chips do have CR4 -- for PSE, VME, etc. (the set of
features varies across the line). Use a fixup as elsewhere or something.