On 6/24/2011 7:38 AM, jean.pihet@xxxxxxxxxxxxxx wrote:
From: Jean Pihet<j-pihet@xxxxxx>
Since cpuidle is a CPU centric framework it decides the MPU
next power state based on the MPU exit_latency and target_residency
figures.
The rest of the power domains get their next power state programmed
from the PM_QOS_DEV_WAKEUP_LATENCY class of the PM QoS framework,
via the device wake-up latency constraints.
Note: the exit_latency and target_residency figures of the MPU
include the MPU itself and the peripherals needed for the MPU to
execute instructions (e.g. main memory, caches, IRQ controller,
MMU etc). Some of those peripherals can belong to other power domains
than the MPU subsystem and so the corresponding latencies must be
included in this figure.
With above comment, I was expecting that the latency numbers
in the table will change.
Tested on OMAP3 Beagleboard in RET/OFF using wake-up latency constraints
on MPU, CORE and PER.
Signed-off-by: Jean Pihet<j-pihet@xxxxxx>
---
arch/arm/mach-omap2/cpuidle34xx.c | 42 +++++++++++-------------------------
1 files changed, 13 insertions(+), 29 deletions(-)
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 4bf6e6e..b43d1d2 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -37,26 +37,26 @@
#ifdef CONFIG_CPU_IDLE
/*
- * The latencies/thresholds for various C states have
+ * The MPU latencies/thresholds for various C states have
* to be configured from the respective board files.
* These are some default values (which might not provide
* the best power savings) used on boards which do not
* pass these details from the board file.
*/
static struct cpuidle_params cpuidle_params_table[] = {
- /* C1 */
+ /* C1 . MPU WFI + Core active */
{2 + 2, 5, 1},
- /* C2 */
+ /* C2 . MPU WFI + Core inactive */
{10 + 10, 30, 1},
- /* C3 */
+ /* C3 . MPU CSWR + Core inactive */
{50 + 50, 300, 1},
- /* C4 */
+ /* C4 . MPU OFF + Core inactive */
{1500 + 1800, 4000, 1},
- /* C5 */
+ /* C5 . MPU RET + Core RET */
{2500 + 7500, 12000, 1},
- /* C6 */
+ /* C6 . MPU OFF + Core RET */
{3000 + 8500, 15000, 1},
- /* C7 */
+ /* C7 . MPU OFF + Core OFF */
{10000 + 30000, 300000, 1},
Latency numbers still seems to include CORE PD latency as
well. Am I missing something Jean?
Regards
Santosh
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