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powermac/cpufreq_32: set non-infinite transition time for 7447A driver

PATCH In review Andreas Schwab 2 participants 2 messages Oct 29, 2012 – Nov 6, 2012

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PowerPC Linux for power macintosh
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Andreas Schwab

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PATCH 1/1 powermac/cpufreq_32: set non-infinite transition time for 7447A driver

The transition time for the 7447A is around 8ms which makes it possible to use the ondemand governor. This has been tested on the iBook G4 (PowerBook6,7).

Signed-off-by Andreas Schwab <[email protected]>
---
 arch/powerpc/platforms/powermac/cpufreq_32.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
arch/powerpc/platforms/powermac/cpufreq_32.c +4 -1
index 6417119..311b804 100644
@@ -55,6 +55,7 @@ static unsigned int low_freq;
 static unsigned int hi_freq;
 static unsigned int cur_freq;
 static unsigned int sleep_freq;
+static unsigned long transition_latency;
 
 /*
  * Different models uses different mechanisms to switch the frequency

@@ -403,7 +404,7 @@ static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	if (policy->cpu != 0)
 		return -ENODEV;
 
-	policy->cpuinfo.transition_latency	= CPUFREQ_ETERNAL;
+	policy->cpuinfo.transition_latency	= transition_latency;
 	policy->cur = cur_freq;
 
 	cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);

@@ -658,12 +659,14 @@ static int __init pmac_cpufreq_setup(void)
 	if (!value)
 		goto out;
 	cur_freq = (*value) / 1000;
+	transition_latency = CPUFREQ_ETERNAL;
 
 	/*  Check for 7447A based MacRISC3 */
 	if (of_machine_is_compatible("MacRISC3") &&
 	    of_get_property(cpunode, "dynamic-power-step", NULL) &&
 	    PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 		pmac_cpufreq_init_7447A(cpunode);
+		transition_latency = 8000000;
 	/* Check for other MacRISC3 machines */
 	} else if (of_machine_is_compatible("PowerBook3,4") ||
 		   of_machine_is_compatible("PowerBook3,5") ||
Signature · 7 lines
1.8.0


-- 
Andreas Schwab, [email protected]
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"And now for something completely different."
Tested-by on v1 1/1
#1 lore raw

On Mon, 2012-10-29 at 10:15 +0100, Andreas Schwab wrote:=20

Quoted 5 lines

The transition time for the 7447A is around 8ms which makes it possible to use the ondemand governor. This has been tested on the iBook G4 (PowerBook6,7).
=20

Signed-off-by Andreas Schwab <[email protected]>
Tested-by Michel D=E4nzer <[email protected]>

--=20
Earthling Michel D=E4nzer | http://www.amd.com
Libre software enthusiast | Debian, X and DRI developer