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Commit 86e13684 authored by Thomas Renninger's avatar Thomas Renninger Committed by Dave Jones
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[CPUFREQ] powernow-k8: Set transition latency to 1 if ACPI tables export 0 



This doesn't fix anything, but it's expected that a transition latency of 0
could cause trouble in the future.

Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: default avatarDave Jones <davej@redhat.com>
parent cef9615a

arch/x86/kernel/cpu/cpufreq/powernow-k8.c

+13 −0
Original line number Diff line number Diff line
@@ -1046,6 +1046,19 @@ static int get_transition_latency(struct powernow_k8_data *data) 
		if (cur_latency > max_latency)

			max_latency = cur_latency;

	}

	if (max_latency == 0) {

		/*

		 * Fam 11h always returns 0 as transition latency.

		 * This is intended and means "very fast". While cpufreq core

		 * and governors currently can handle that gracefully, better

		 * set it to 1 to avoid problems in the future.

		 * For all others it's a BIOS bug.

		 */

		if (!boot_cpu_data.x86 == 0x11)

			printk(KERN_ERR FW_WARN PFX "Invalid zero transition "

				"latency\n");

		max_latency = 1;

	}

	/* value in usecs, needs to be in nanoseconds */

	return 1000 * max_latency;

}