Re: [RESEND] Fast TSC calibration fails with v3.14-rc1 and later

[Julian Wollrath <jwollrath@web.de>]

> > But I wonder: Can we simply enable SCI later?  In other words, can
> > we split acpi_early_init() so that the part before
> > acpi_enable_subsystem() is done before timekeeping_init() and the
> > part including and after is done right after anon_vma_init()?
> > Would the TAD initialization work then?
> 
> Below is a patch implementing that idea.  Julian, can you please test
> this one too?
That patch also fixes the problem, thank you.

Cheers,
Julian

> 
> Rafael
> 
> ---
>  drivers/acpi/bus.c   |   20 +++++++++++++++-----
>  include/linux/acpi.h |    1 +
>  init/main.c          |    1 +
>  3 files changed, 17 insertions(+), 5 deletions(-)
> 
> Index: linux-pm/drivers/acpi/bus.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/bus.c
> +++ linux-pm/drivers/acpi/bus.c
> @@ -494,11 +494,21 @@ void __init acpi_early_init(void)
>  	}
>  
>  	status = acpi_load_tables();
> -	if (ACPI_FAILURE(status)) {
> -		printk(KERN_ERR PREFIX
> -		       "Unable to load the System Description
> Tables\n");
> -		goto error0;
> -	}
> +	if (ACPI_SUCCESS(status))
> +		return;
> +
> +	printk(KERN_ERR PREFIX "Unable to load the System
> Description Tables\n"); +
> + error0:
> +	disable_acpi();
> +}
> +
> +void __init acpi_subsystem_init(void)
> +{
> +	acpi_status status;
> +
> +	if (acpi_disabled)
> +		return;
>  
>  #ifdef CONFIG_X86
>  	if (!acpi_ioapic) {
> Index: linux-pm/include/linux/acpi.h
> ===================================================================
> --- linux-pm.orig/include/linux/acpi.h
> +++ linux-pm/include/linux/acpi.h
> @@ -401,6 +401,7 @@ extern acpi_status acpi_pci_osc_control_
>  #define ACPI_OST_SC_INSERT_NOT_SUPPORTED	0x82
>  
>  extern void acpi_early_init(void);
> +extern void acpi_subsystem_init(void);
>  
>  extern int acpi_nvs_register(__u64 start, __u64 size);
>  
> Index: linux-pm/init/main.c
> ===================================================================
> --- linux-pm.orig/init/main.c
> +++ linux-pm/init/main.c
> @@ -613,6 +613,7 @@ asmlinkage void __init start_kernel(void
>  	calibrate_delay();
>  	pidmap_init();
>  	anon_vma_init();
> +	acpi_subsystem_init();
>  #ifdef CONFIG_X86
>  	if (efi_enabled(EFI_RUNTIME_SERVICES))
>  		efi_enter_virtual_mode();
>