If autoidle for DPLL4 is enabled in the stored scratchpad value of CM_AUTOIDLE_PLL then there is an added delay by the boot ROM when coming out of OFF mode. The patch disables this bitfield in the stored scratchpad value.
This should significantly reduce CORE OFF latency and also bring down the threshold for CORE OFF, making OFF affordable even with smaller sleep times. This patch however does not optimize the C state threshold for CORE OFF states based on the new latency. Signed-off-by: Rajendra Nayak <[email protected]> --- arch/arm/mach-omap2/control.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c index c9407c0..a7159a9 100644 --- a/arch/arm/mach-omap2/control.c +++ b/arch/arm/mach-omap2/control.c @@ -238,6 +238,13 @@ void omap3_save_scratchpad_contents(void) cm_read_mod_reg(PLL_MOD, CM_CLKEN); prcm_block_contents.cm_autoidle_pll = cm_read_mod_reg(PLL_MOD, OMAP3430_CM_AUTOIDLE_PLL); + /* + * ROM restore takes 20mS longer if PER idle is enabled before OFF. + * Clear feature before sleep. The origional idle state is + * restored by software as part of wake procedure. + */ + prcm_block_contents.cm_autoidle_pll &= ~OMAP3430_AUTO_PERIPH_DPLL_MASK; + prcm_block_contents.cm_clksel1_pll = cm_read_mod_reg(PLL_MOD, OMAP3430_CM_CLKSEL1_PLL); prcm_block_contents.cm_clksel2_pll = -- 1.5.4.7 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
