Re: [PATCH] Re: [linux-pm] Invalid opcode on resume from STR on AsusP4P800-VM

[Alan Stern]

On Sat, 5 Jun 2010, Ondrej Zary wrote:

> > > Thanks, it does not crash with "idle=halt" or "idle=poll". According to
> > > this: http://siyobik.info/index.php?module=x86&id=215
> > > the MWAIT instruction can be enabled/disabled in IA32_MISC_ENABLES MSR.
> > > Kernel probably should enable it at boot and also on resume.
> > > Here's some more info:
> > > http://software.intel.com/en-us/forums/showthread.php?t=63654
> >
> > That could be the answer.  Clearly this should be handled by the
> > arch-specific boot/setup code.  I don't know enough about it, but other
> > people do.
> 
> Here's a patch that fixes the problem. I don't know how many machines will
> it break...
> 
> 
> diff -urp linux-2.6.35-rc1-git2-orig/arch/x86/include/asm/suspend_32.h linux-2.6.35-rc1-git2/arch/x86/include/asm/suspend_32.h
> --- linux-2.6.35-rc1-git2-orig/arch/x86/include/asm/suspend_32.h	2010-05-30 22:21:02.000000000 +0200
> +++ linux-2.6.35-rc1-git2/arch/x86/include/asm/suspend_32.h	2010-06-04 23:52:22.000000000 +0200
> @@ -15,6 +15,7 @@ static inline int arch_prepare_suspend(v
>  struct saved_context {
>  	u16 es, fs, gs, ss;
>  	unsigned long cr0, cr2, cr3, cr4;
> +	unsigned long misc_enable;
>  	struct desc_ptr gdt;
>  	struct desc_ptr idt;
>  	u16 ldt;
> diff -urp linux-2.6.35-rc1-git2-orig/arch/x86/include/asm/suspend_64.h linux-2.6.35-rc1-git2/arch/x86/include/asm/suspend_64.h
> --- linux-2.6.35-rc1-git2-orig/arch/x86/include/asm/suspend_64.h	2010-05-30 22:21:02.000000000 +0200
> +++ linux-2.6.35-rc1-git2/arch/x86/include/asm/suspend_64.h	2010-06-04 23:52:21.000000000 +0200
> @@ -27,6 +27,7 @@ struct saved_context {
>  	u16 ds, es, fs, gs, ss;
>  	unsigned long gs_base, gs_kernel_base, fs_base;
>  	unsigned long cr0, cr2, cr3, cr4, cr8;
> +	unsigned long misc_enable;
>  	unsigned long efer;
>  	u16 gdt_pad;
>  	u16 gdt_limit;
> diff -urp linux-2.6.35-rc1-git2-orig/arch/x86/power/cpu.c linux-2.6.35-rc1-git2/arch/x86/power/cpu.c
> --- linux-2.6.35-rc1-git2-orig/arch/x86/power/cpu.c	2010-05-30 22:21:02.000000000 +0200
> +++ linux-2.6.35-rc1-git2/arch/x86/power/cpu.c	2010-06-04 23:50:52.000000000 +0200
> @@ -105,6 +105,7 @@ static void __save_processor_state(struc
>  	ctxt->cr4 = read_cr4();
>  	ctxt->cr8 = read_cr8();
>  #endif
> +	rdmsrl(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
>  }
>  
>  /* Needed by apm.c */
> @@ -152,6 +153,7 @@ static void fix_processor_context(void)
>   */
>  static void __restore_processor_state(struct saved_context *ctxt)
>  {
> +	wrmsrl(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
>  	/*
>  	 * control registers
>  	 */

It fixes the problem on my machine!  I say go ahead and submit it.

Tested-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

Alan Stern

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