From: Jon Hunter <jon-hunter@ti.com> To: Paul Walmsley <paul@pwsan.com> Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "Benoît Cousson" <b-cousson@ti.com> Subject: Re: [PATCH 09/12] ARM: OMAP2+: powerdomain: skip register reads for powerdomains known to be on Date: Wed, 19 Dec 2012 15:09:31 -0600 [thread overview] Message-ID: <50D22D0B.3050502@ti.com> (raw) In-Reply-To: <20121209200327.3196.27686.stgit@dusk.lan> Hi Paul, On 12/09/2012 02:03 PM, Paul Walmsley wrote: > There's no need to determine the current power state for powerdomains > that must be on while the kernel is running. We mark these > powerdomains with a new flag, PWRDM_ACTIVE_WITH_KERNEL. Any > powerdomain marked with that flag is reported as being in the ON power > state while the kernel is running. > > Signed-off-by: Paul Walmsley <paul@pwsan.com> > Cc: Benoît Cousson <b-cousson@ti.com> > --- > arch/arm/mach-omap2/powerdomain.c | 9 ++++++--- > arch/arm/mach-omap2/powerdomain.h | 4 ++++ > arch/arm/mach-omap2/powerdomains2xxx_data.c | 2 ++ > arch/arm/mach-omap2/powerdomains33xx_data.c | 3 ++- > arch/arm/mach-omap2/powerdomains3xxx_data.c | 9 ++++++--- > arch/arm/mach-omap2/powerdomains44xx_data.c | 5 ++++- > 6 files changed, 24 insertions(+), 8 deletions(-) [snip] > diff --git a/arch/arm/mach-omap2/powerdomains44xx_data.c b/arch/arm/mach-omap2/powerdomains44xx_data.c > index 704664c..b64213c 100644 > --- a/arch/arm/mach-omap2/powerdomains44xx_data.c > +++ b/arch/arm/mach-omap2/powerdomains44xx_data.c > @@ -53,7 +53,8 @@ static struct powerdomain core_44xx_pwrdm = { > [3] = PWRSTS_ON, /* ducati_l2ram */ > [4] = PWRSTS_ON, /* ducati_unicache */ > }, > - .flags = PWRDM_HAS_LOWPOWERSTATECHANGE, > + .flags = (PWRDM_HAS_LOWPOWERSTATECHANGE | > + PWRDM_ACTIVE_WITH_KERNEL), > }; My understanding is that for OMAP4 devices, the core power domain may not be active the same time as the MPU power domain. The Cortex-A9 has the ability to access some peripherals (such as timer, McBSP) via a private bus that does not require the core domain to be active. This is a difference from OMAP3 devices, where the core would always be on with the MPU power domain. Hopefully, Benoit will chime in if I have gotten this wrong ;-) Cheers Jon -- 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
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From: jon-hunter@ti.com (Jon Hunter) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 09/12] ARM: OMAP2+: powerdomain: skip register reads for powerdomains known to be on Date: Wed, 19 Dec 2012 15:09:31 -0600 [thread overview] Message-ID: <50D22D0B.3050502@ti.com> (raw) In-Reply-To: <20121209200327.3196.27686.stgit@dusk.lan> Hi Paul, On 12/09/2012 02:03 PM, Paul Walmsley wrote: > There's no need to determine the current power state for powerdomains > that must be on while the kernel is running. We mark these > powerdomains with a new flag, PWRDM_ACTIVE_WITH_KERNEL. Any > powerdomain marked with that flag is reported as being in the ON power > state while the kernel is running. > > Signed-off-by: Paul Walmsley <paul@pwsan.com> > Cc: Beno?t Cousson <b-cousson@ti.com> > --- > arch/arm/mach-omap2/powerdomain.c | 9 ++++++--- > arch/arm/mach-omap2/powerdomain.h | 4 ++++ > arch/arm/mach-omap2/powerdomains2xxx_data.c | 2 ++ > arch/arm/mach-omap2/powerdomains33xx_data.c | 3 ++- > arch/arm/mach-omap2/powerdomains3xxx_data.c | 9 ++++++--- > arch/arm/mach-omap2/powerdomains44xx_data.c | 5 ++++- > 6 files changed, 24 insertions(+), 8 deletions(-) [snip] > diff --git a/arch/arm/mach-omap2/powerdomains44xx_data.c b/arch/arm/mach-omap2/powerdomains44xx_data.c > index 704664c..b64213c 100644 > --- a/arch/arm/mach-omap2/powerdomains44xx_data.c > +++ b/arch/arm/mach-omap2/powerdomains44xx_data.c > @@ -53,7 +53,8 @@ static struct powerdomain core_44xx_pwrdm = { > [3] = PWRSTS_ON, /* ducati_l2ram */ > [4] = PWRSTS_ON, /* ducati_unicache */ > }, > - .flags = PWRDM_HAS_LOWPOWERSTATECHANGE, > + .flags = (PWRDM_HAS_LOWPOWERSTATECHANGE | > + PWRDM_ACTIVE_WITH_KERNEL), > }; My understanding is that for OMAP4 devices, the core power domain may not be active the same time as the MPU power domain. The Cortex-A9 has the ability to access some peripherals (such as timer, McBSP) via a private bus that does not require the core domain to be active. This is a difference from OMAP3 devices, where the core would always be on with the MPU power domain. Hopefully, Benoit will chime in if I have gotten this wrong ;-) Cheers Jon
next prev parent reply other threads:[~2012-12-19 21:09 UTC|newest] Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-12-09 20:02 [PATCH 00/12] ARM: OMAP2+: powerdomain updates after the functional power state conversion Paul Walmsley 2012-12-09 20:02 ` Paul Walmsley 2012-12-09 20:02 ` [PATCH 01/12] ARM: OMAP2+: powerdomain: consolidate arch_pwrdm check code Paul Walmsley 2012-12-09 20:02 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 02/12] ARM: OMAP2+: PM/powerdomain: move the power state time tracking into the powerdomain code Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 03/12] ARM: OMAP2+: powerdomain: split pwrdm_state_switch() Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 04/12] ARM: OMAP2+: PM: clean up some debugfs functions Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 05/12] ARM: OMAP2+: powerdomain: remove some redundant checks; add some notes Paul Walmsley 2012-12-09 20:03 ` [PATCH 06/12] ARM: OMAP2+: CM: use the cached copy of the clockdomain's hwsup state Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 07/12] ARM: OMAP2+: powerdomain: cache the powerdomain next power state Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 08/12] ARM: OMAP2+: powerdomain: cache the powerdomain's previous " Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 09/12] ARM: OMAP2+: powerdomain: skip register reads for powerdomains known to be on Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-12 10:22 ` Vaibhav Hiremath 2012-12-12 10:22 ` Vaibhav Hiremath 2012-12-19 21:09 ` Jon Hunter [this message] 2012-12-19 21:09 ` Jon Hunter 2012-12-20 17:22 ` Paul Walmsley 2012-12-20 17:22 ` Paul Walmsley 2012-12-21 6:33 ` Santosh Shilimkar 2012-12-21 6:33 ` Santosh Shilimkar 2012-12-26 6:21 ` Bedia, Vaibhav 2012-12-26 6:21 ` Bedia, Vaibhav 2012-12-26 6:31 ` Bedia, Vaibhav 2012-12-26 6:31 ` Bedia, Vaibhav 2012-12-26 20:49 ` Paul Walmsley 2012-12-26 20:49 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 10/12] ARM: OMAP2+: powerdomain: skip previous-power-state read if next_pwrst is ON Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 11/12] ARM: OMAP2xxx: powerdomain: add previous power state tracking Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2012-12-09 20:03 ` [PATCH 12/12] ARM: OMAP2xxx: PM: add pwrdm_(pre|post)_transition() calls to the 2xxx PM code Paul Walmsley 2012-12-09 20:03 ` Paul Walmsley 2013-01-04 14:26 ` [PATCH 00/12] ARM: OMAP2+: powerdomain updates after the functional power state conversion Tero Kristo 2013-01-04 14:26 ` Tero Kristo
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