ACPI: Fix regression where _PPC is not read at boot even when ignore_ppc=0

Earlier, Ingo Molnar posted a patch to make it so that the kernel would avoid
reading _PPC on his broken T60. Unfortunately, it seems that with Thomas
Renninger's patch last July to eliminate _PPC evaluations when the processor
driver loads, the kernel never actually reads _PPC at all! This is problematic
if you happen to boot your non-T60 computer in a state where the BIOS _wants_
_PPC to be something other than zero.

So, put the _PPC evaluation back into acpi_processor_get_performance_info if
ignore_ppc isn't 1.

Signed-off-by: Darrick J. Wong <[e-mail]>
Signed-off-by: Len Brown <[e-mail]>

drivers/acpi/processor_perflib.c

···
 	if (result)
 		goto update_bios;
 
-	return 0;
+	/* We need to call _PPC once when cpufreq starts */
+	if (ignore_ppc != 1)
+		result = acpi_processor_get_platform_limit(pr);
+
+	return result;
 
 	/*
 	 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that