From: Jean Pihet <j-pihet@xxxxxx> Update the data from the measurements performed at HW and SW levels. Cf. http://www.omappedia.org/wiki/Power_Management_Device_Latencies_Measurement for a detailed explanation on where are the numbers coming from. ToDo: - Measure the wake-up latencies for all power domains for OMAP3 - Correct some numbers when sys_clkreq and sys_offmode are supported Signed-off-by: Jean Pihet <j-pihet@xxxxxx> --- arch/arm/mach-omap2/cpuidle34xx.c | 52 +++++++++++++++++++++++------------- 1 files changed, 33 insertions(+), 19 deletions(-) diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c index c67835f..3caa932 100644 --- a/arch/arm/mach-omap2/cpuidle34xx.c +++ b/arch/arm/mach-omap2/cpuidle34xx.c @@ -40,27 +40,41 @@ #ifdef CONFIG_CPU_IDLE /* - * 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. + * The MPU latency and threshold values for the C-states are the worst case + * values from the HW and SW, as described in details at + * http://www.omappedia.org/wiki/Power_Management_Device_Latencies_Measurement#cpuidle_results + * + * Measurements conditions and remarks: + * . the measurements have been performed at OPP50 + * . the sys_offmode signal is not supported and so not used for the + * measurements. Instead the latency and threshold values for C9 are + * corrected with the value for Triton 2, which is 11.5ms + * . the sys_clkreq signal is not used and so a correction is needed - TBD + * . the sys_clkoff signal is supported, this value need to be corrected with + * the correct value of SYSCLK on/off timings (1ms for sysclk on, 2.5ms + * for sysclk off) + * . in order to force the cpuidle algorithm to chose the power efficient + * C-states (C1, C3, C5, C7) in preference, the other C-states have a + * threshold value equal to the next power efficient C-state + * + * The latency and threshold values can be overriden by data from the board + * files, using omap3_pm_init_cpuidle. */ static struct cpuidle_params cpuidle_params_table[] = { - /* C1 */ - {2 + 2, 5, 1}, - /* C2 */ - {10 + 10, 30, 1}, - /* C3 */ - {50 + 50, 300, 1}, - /* C4 */ - {1500 + 1800, 4000, 1}, - /* C5 */ - {2500 + 7500, 12000, 1}, - /* C6 */ - {3000 + 8500, 15000, 1}, - /* C7 */ - {10000 + 30000, 300000, 1}, + /* C1 . MPU WFI + Core active */ + {73 + 78, 152, 1}, + /* C2 . MPU WFI + Core inactive */ + {165 + 88, 345, 1}, + /* C3 . MPU CSWR + Core inactive */ + {163 + 182, 345, 1}, + /* C4 . MPU OFF + Core inactive */ + {2852 + 605, 150000, 1}, + /* C5 . MPU RET + Core RET */ + {800 + 366, 2120, 1}, + /* C6 . MPU OFF + Core RET */ + {4080 + 801, 215000, 1}, + /* C7 . MPU OFF + Core OFF */ + {4300 + 13000, 215000, 1}, }; #define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table) -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
