Messages in this thread | | | Date | Mon, 18 Aug 2008 05:14:50 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH] Fix i486 suspend to disk CR4 oops |
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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.
Maciej
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