Re: [stable PATCH 2.6.21] ACPICA: Ignore ACPI table signature for Load() operator

["Oliver Pinter" <oliver.pntr@gmail.com>]

thx picked up for 2.6.22

On 6/19/08, Len Brown <lenb@kernel.org> wrote:
> From: Bob Moore <robert.moore@intel.com>
>
> upstream bc45b1d39a925b56796bebf8a397a0491489d85c
>
> Only "SSDT" is acceptable to the ACPI spec, but tables are
> seen with OEMx and null sigs. Therefore, signature validation
> is worthless.  Apparently MS ACPI accepts such signatures, ACPICA
> must be compatible.
>
> Without this patch booting with acpi_osi="!Windows 2006" is required
> for several machines to function properly with cpufreq.
>
> http://bugzilla.kernel.org/show_bug.cgi?id=9919
> http://bugzilla.kernel.org/show_bug.cgi?id=10383
> http://bugzilla.kernel.org/show_bug.cgi?id=10454
> https://bugzilla.novell.com/show_bug.cgi?id=396311
>
> Signed-off-by: Bob Moore <robert.moore@intel.com>
> Signed-off-by: Lin Ming <ming.m.lin@intel.com>
> Signed-off-by: Len Brown <len.brown@intel.com>
> ---
>  drivers/acpi/tables/tbinstal.c |   25 +++++++------------------
>  1 files changed, 7 insertions(+), 18 deletions(-)
>
> Index: linux-2.6.21.y/drivers/acpi/tables/tbinstal.c
> ===================================================================
> --- linux-2.6.21.y.orig/drivers/acpi/tables/tbinstal.c
> +++ linux-2.6.21.y/drivers/acpi/tables/tbinstal.c
> @@ -123,17 +123,13 @@ acpi_tb_add_table(struct acpi_table_desc
>  		}
>  	}
>
> -	/* The table must be either an SSDT or a PSDT */
> -
> -	if ((!ACPI_COMPARE_NAME(table_desc->pointer->signature, ACPI_SIG_PSDT))
> -	    &&
> -	    (!ACPI_COMPARE_NAME(table_desc->pointer->signature, ACPI_SIG_SSDT)))
> -	{
> -		ACPI_ERROR((AE_INFO,
> -			    "Table has invalid signature [%4.4s], must be SSDT or PSDT",
> -			    table_desc->pointer->signature));
> -		return_ACPI_STATUS(AE_BAD_SIGNATURE);
> -	}
> +	/*
> +	 * Originally, we checked the table signature for "SSDT" or "PSDT" here.
> +	 * Next, we added support for OEMx tables, signature "OEM".
> +	 * Valid tables were encountered with a null signature, so we've just
> +	 * given up on validating the signature, since it seems to be a waste
> +	 * of code. The original code was removed (05/2008).
> +	 */
>
>  	(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
>
> --
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-- 
Thanks,
Oliver