From: Len Brown <len.brown@intel.com>
Date: Fri, 24 Apr 2009 03:21:29 +0000 (-0400)
Subject: ACPI: prevent processor.max_cstate=0 boot crash
X-Git-Tag: v2.6.30-rc4~50^2~3^2
X-Git-Url: http://ftp.safe.ca/?a=commitdiff_plain;h=615dfd93e2346b604232b559e7ea0835d24abe26;p=safe%2Fjmp%2Flinux-2.6

ACPI: prevent processor.max_cstate=0 boot crash

As processor.max_cstate is an init-time-only modparam,
sanity checking it at init-time is sufficient.

http://bugzilla.kernel.org/show_bug.cgi?id=13142

Signed-off-by: Len Brown <len.brown@intel.com>
---

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 6fe1214..436127e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1037,6 +1037,9 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
 		dev->states[i].desc[0] = '\0';
 	}
 
+	if (max_cstate == 0)
+		max_cstate = 1;
+
 	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 		cx = &pr->power.states[i];
 		state = &dev->states[count];