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acpi: check _PSS invalidation when BIOS report _PSS with 0x80000000

PATCH NAK [email protected] 2 participants 2 messages Apr 11, 2009 – Apr 20, 2009 ACPI

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PATCH 1/4 acpi: check _PSS invalidation when BIOS report _PSS with 0x80000000

From: Youquan, Song <[email protected]>

When cpu frequencey scaling is disabled, some BIOSes report _PSS with all 0x80000000. If the kernel treats this case as valid, the kernel will boot crash when load cpufreq govenors.

So in order to cover more buggy BIOSs, the patch just check _PSS core frequency invalidation.

Quoted 6 lines · On Sun, 15 Mar 2009 23:22:37 -0400 (EDT) Len Brown <[email protected]> wrote:

NAK -- per previous discussion on the list.

This patch is not the right way to address this issue, which is reported here, BTW:

https://bugzilla.redhat.com/show_bug.cgi?id=467941

---

 drivers/acpi/processor_perflib.c |    9 +++++++++
 1 file changed, 9 insertions(+)
drivers/acpi/processor_perflib.c renamed from drivers/acpi/processor_perflib.c~acpi-check-_pss-invalidation-when-bios-report-_pss-with-all-0x80000000 +9 -0
diff -puN drivers/acpi/processor_perflib.c~acpi-check-_pss-invalidation-when-bios-report-_pss-with-all-0x80000000 drivers/acpi/processor_perflib.c
@@ -42,6 +42,7 @@
 #define ACPI_PROCESSOR_CLASS		"processor"
 #define ACPI_PROCESSOR_FILE_PERFORMANCE	"performance"
 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
+#define ACPI_PROCESSOR_PSS_INVALID	0x80000000
 ACPI_MODULE_NAME("processor_perflib");
 
 static DEFINE_MUTEX(performance_mutex);
@@ -316,6 +317,14 @@ static int acpi_processor_get_performanc
 			kfree(pr->performance->states);
 			goto end;
 		}
+
+		if (px->core_frequency == ACPI_PROCESSOR_PSS_INVALID) {
+			printk(KERN_ERR PREFIX
+				    "P-states disabled in the BIOS\n");
+			result = -EFAULT;
+			kfree(pr->performance->states);
+			goto end;
+		}
 	}
 
       end:

_

reviewer NAK
#1 lore raw

NAK

This is a recording.

Andrew, please remove this patch from your series
per issues earlier discussed on the list.

thanks,
Len Brown, Intel Open Source Technology Center