From mboxrd@z Thu Jan 1 00:00:00 1970 From: jouni.hogander@nokia.com (=?utf-8?Q?H=C3=B6gander?= Jouni) Subject: Re: [PATCH 01/04] OMAP3: PM: Disable PER DPLL idle before OFF, reduces OFF latency by 20ms Date: Tue, 16 Jun 2009 15:52:51 +0300 Message-ID: <87fxe0basc.fsf@trdhcp146196.ntc.nokia.com> References: <1245153154-1876-1-git-send-email-rnayak@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp.nokia.com ([192.100.105.134]:65091 "EHLO mgw-mx09.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753268AbZFPMys convert rfc822-to-8bit (ORCPT ); Tue, 16 Jun 2009 08:54:48 -0400 In-Reply-To: <1245153154-1876-1-git-send-email-rnayak@ti.com> (ext Rajendra Nayak's message of "Tue\, 16 Jun 2009 13\:52\:31 +0200") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: ext Rajendra Nayak Cc: "linux-omap@vger.kernel.org" , "dderrick@ti.com" , "r-woodruff2@ti.com" ext Rajendra Nayak 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? > > Signed-off-by: Rajendra Nayak > --- > 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/cont= rol.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 =3D > 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 &=3D ~OMAP3430_AUTO_PERIPH_DPLL= _MASK; > + > prcm_block_contents.cm_clksel1_pll =3D > cm_read_mod_reg(PLL_MOD, OMAP3430_CM_CLKSEL1_PLL); > prcm_block_contents.cm_clksel2_pll =3D > --=20 > 1.5.4.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --=20 Jouni H=C3=B6gander -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html