>-----Original Message----- >From: Högander Jouni [mailto:jouni.hogander@xxxxxxxxx] >Sent: Tuesday, June 16, 2009 6:23 PM >To: Nayak, Rajendra >Cc: linux-omap@xxxxxxxxxxxxxxx; Derrick, David; Woodruff, Richard >Subject: Re: [PATCH 01/04] OMAP3: PM: Disable PER DPLL idle >before OFF, reduces OFF latency by 20ms > >ext Rajendra Nayak <rnayak@xxxxxx> writes: > >> 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. > >Do you have any numbers to give on what is the impact to consumption? Not yet, I will post some after some profiling. > >> >> Signed-off-by: Rajendra Nayak <rnayak@xxxxxx> >> --- >> 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 majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >-- >Jouni Högander > >��.n��������+%������w��{.n�����{�������ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
