From: Russell King - ARM Linux <linux@arm.linux.org.uk> To: Colin Cross <ccross@android.com> Cc: Will Deacon <will.deacon@arm.com>, Santosh Shilimkar <santosh.shilimkar@ti.com>, Catalin Marinas <Catalin.Marinas@arm.com>, Linus Walleij <linus.walleij@stericsson.com>, konkers@android.com, Tony Lindgren <tony@atomide.com>, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, olof@lixom.net, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 04/28] ARM: mm: cache-l2x0: Add support for re-enabling l2x0 Date: Fri, 4 Feb 2011 23:43:31 +0000 [thread overview] Message-ID: <20110204234331.GF8732@n2100.arm.linux.org.uk> (raw) In-Reply-To: <AANLkTi=cTXmQFm_s5OL2pGyyaFv5UR_f9MV=S5Ajx0tu@mail.gmail.com> On Fri, Feb 04, 2011 at 05:32:26PM -0600, Colin Cross wrote: > On Tue, Jan 25, 2011 at 12:39 PM, Will Deacon <will.deacon@arm.com> wrote: > > Well if you set the priority fields in the notifier blocks correctly > > then you can just return NOTIFY_STOP when you've saved/restored as much > > as you want. This assumes of course that you can identify which power > > mode you're entering/leaving and that each one is `deeper' than the previous. > > I doubt its possible to create an order that will work for all > architectures, and returning NOTIFY_STOP would require the decision on > when to finish to be made by the notifier block instead of the > platform code. > > Tegra has three possible idle modes: > > 1. WFI - nothing reset > 2. CPU, TWD, L1, GIC lost, L2 needs to be disabled but not reset > 3. CPU, TWD, L1, GIC, and L2 lost (2) and (3) don't sound like per-cpu modes but system modes. If you're having to disable L2, then your other CPU can't be active. > CPU and L1 are already handled by the platform-specific suspend code. > TWD is handled by the clockevents broadcast notifiers. That leaves L2 > and GIC. GIC can be handled in just the same way - upon a CPU idling and it being decided that the CPU should enter low power mode, the idle states are entered which does what's required with TWD, L1, VFP, Neon, etc. We just need the GIC CPU interface included in there. When both CPUs are idled, then the L2 comes into play, and then modes (2) and (3) become possible and this is where you start doing the extra stuff. Note that you have to do it that way anyway, because you can't save the state of the other CPU's GIC without doing an IPI call, which could kick it out of its idle mode.
WARNING: multiple messages have this Message-ID (diff)
From: linux@arm.linux.org.uk (Russell King - ARM Linux) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 04/28] ARM: mm: cache-l2x0: Add support for re-enabling l2x0 Date: Fri, 4 Feb 2011 23:43:31 +0000 [thread overview] Message-ID: <20110204234331.GF8732@n2100.arm.linux.org.uk> (raw) In-Reply-To: <AANLkTi=cTXmQFm_s5OL2pGyyaFv5UR_f9MV=S5Ajx0tu@mail.gmail.com> On Fri, Feb 04, 2011 at 05:32:26PM -0600, Colin Cross wrote: > On Tue, Jan 25, 2011 at 12:39 PM, Will Deacon <will.deacon@arm.com> wrote: > > Well if you set the priority fields in the notifier blocks correctly > > then you can just return NOTIFY_STOP when you've saved/restored as much > > as you want. This assumes of course that you can identify which power > > mode you're entering/leaving and that each one is `deeper' than the previous. > > I doubt its possible to create an order that will work for all > architectures, and returning NOTIFY_STOP would require the decision on > when to finish to be made by the notifier block instead of the > platform code. > > Tegra has three possible idle modes: > > 1. WFI - nothing reset > 2. CPU, TWD, L1, GIC lost, L2 needs to be disabled but not reset > 3. CPU, TWD, L1, GIC, and L2 lost (2) and (3) don't sound like per-cpu modes but system modes. If you're having to disable L2, then your other CPU can't be active. > CPU and L1 are already handled by the platform-specific suspend code. > TWD is handled by the clockevents broadcast notifiers. That leaves L2 > and GIC. GIC can be handled in just the same way - upon a CPU idling and it being decided that the CPU should enter low power mode, the idle states are entered which does what's required with TWD, L1, VFP, Neon, etc. We just need the GIC CPU interface included in there. When both CPUs are idled, then the L2 comes into play, and then modes (2) and (3) become possible and this is where you start doing the extra stuff. Note that you have to do it that way anyway, because you can't save the state of the other CPU's GIC without doing an IPI call, which could kick it out of its idle mode.
next prev parent reply other threads:[~2011-02-04 23:43 UTC|newest] Thread overview: 137+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-01-24 2:01 [PATCH v2 00/28] Updates for Tegra support in 2.6.39 Colin Cross 2011-01-24 2:01 ` [PATCH v2 01/28] ARM: tegra: irq: Rename gic pointers to avoid conflicts Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-26 7:10 ` Colin Cross 2011-01-26 7:10 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 02/28] ARM: gic: Add functions to save and restore gic state Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-02-01 13:03 ` Russell King - ARM Linux 2011-02-01 13:03 ` Russell King - ARM Linux 2011-01-24 2:01 ` [PATCH v2 03/28] ARM: gic: Export irq chip functions Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 6:39 ` Santosh Shilimkar 2011-01-24 6:39 ` Santosh Shilimkar 2011-01-24 2:01 ` [PATCH v2 04/28] ARM: mm: cache-l2x0: Add support for re-enabling l2x0 Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-25 15:14 ` Catalin Marinas 2011-01-25 15:14 ` Catalin Marinas 2011-01-25 15:41 ` Russell King - ARM Linux 2011-01-25 15:41 ` Russell King - ARM Linux 2011-01-25 18:14 ` Catalin Marinas 2011-01-25 18:14 ` Catalin Marinas 2011-01-25 18:32 ` Santosh Shilimkar 2011-01-25 18:32 ` Santosh Shilimkar 2011-01-25 18:39 ` Will Deacon [not found] ` <-8932138696981683633@unknownmsgid> 2011-02-04 23:32 ` Colin Cross 2011-02-04 23:32 ` Colin Cross 2011-02-04 23:32 ` Colin Cross 2011-02-04 23:43 ` Russell King - ARM Linux [this message] 2011-02-04 23:43 ` Russell King - ARM Linux [not found] ` <20110204234331.GF8732-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> 2011-02-05 1:44 ` Colin Cross 2011-02-05 1:44 ` Colin Cross 2011-02-05 1:44 ` Colin Cross [not found] ` <AANLkTi=fHnivHXHnYrQvdP6JWbEA3t1X3DuBxj5gN3H0-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2011-02-05 7:51 ` Santosh Shilimkar 2011-02-05 7:51 ` Santosh Shilimkar 2011-02-05 7:51 ` Santosh Shilimkar [not found] ` <1bebe4b5c8590059b70a146d5486fa6a-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2011-02-05 9:47 ` Russell King - ARM Linux 2011-02-05 9:47 ` Russell King - ARM Linux 2011-02-05 9:47 ` Russell King - ARM Linux 2011-02-05 10:41 ` [PATCH v2 04/28] ARM: mm: cache-l2x0: Add support forre-enabling l2x0 Santosh Shilimkar 2011-02-05 10:41 ` Santosh Shilimkar 2011-02-05 16:36 ` Colin Cross 2011-02-05 16:36 ` Colin Cross [not found] ` <AANLkTik_r4k_5o+F47vRbGPcWLwfgHgWqhym49XfhBZ9-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2011-02-07 6:13 ` Santosh Shilimkar 2011-02-07 6:13 ` Santosh Shilimkar 2011-02-07 6:13 ` Santosh Shilimkar 2011-01-24 2:01 ` [PATCH v2 05/28] ARM: tegra: Centralize macros to define debug uart base Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 06/28] ARM: tegra: Add api to control internal powergating Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 07/28] ARM: tegra: irqs: Update irq list Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 08/28] ARM: tegra: Add prototypes for subsystem suspend functions Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 09/28] ARM: tegra: clock: Suspend fixes, and add new clocks Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 10/28] ARM: tegra: pinmux: Add missing drive pingroups and fix suspend Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 11/28] ARM: tegra: timer: Add idle and suspend support to timers Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 12/28] ARM: tegra: irq: Add support for suspend wake sources Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 13/28] ARM: tegra: Add suspend and hotplug support Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 7:31 ` Colin Cross 2011-01-24 7:31 ` Colin Cross 2011-01-24 9:07 ` Russell King - ARM Linux 2011-01-24 9:07 ` Russell King - ARM Linux 2011-01-24 9:26 ` Colin Cross 2011-01-24 9:26 ` Colin Cross 2011-01-24 10:15 ` Russell King - ARM Linux 2011-01-24 10:15 ` Russell King - ARM Linux 2011-01-24 2:01 ` [PATCH v2 14/28] ARM: tegra: irq: Add set_wake and set_type support for suspend Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 15/28] ARM: tegra: irq: Add debugfs file to show wake irqs Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-27 19:45 ` Stephen Boyd 2011-01-27 19:45 ` Stephen Boyd 2011-01-24 2:01 ` [PATCH v2 16/28] ARM: tegra: irq: Implement retrigger Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 17/28] ARM: tegra: gpio: Add support for waking from suspend Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 18/28] ARM: tegra: add CPU_IDLE driver Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-27 20:38 ` Stephen Boyd 2011-01-27 20:38 ` Stephen Boyd 2011-01-27 21:51 ` Colin Cross 2011-01-27 21:51 ` Colin Cross 2011-01-27 22:07 ` Colin Cross 2011-01-27 22:07 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 19/28] ARM: tegra: iomap: Add missing devices, fix use of SZ_8, SZ_64 Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 20/28] ARM: tegra: cpufreq: Disable cpufreq during suspend Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 14:41 ` Mark Brown 2011-01-24 14:41 ` Mark Brown 2011-01-24 18:50 ` Colin Cross 2011-01-24 18:50 ` Colin Cross 2011-01-24 19:35 ` Mark Brown 2011-01-24 19:35 ` Mark Brown 2011-01-24 19:52 ` Colin Cross 2011-01-24 19:52 ` Colin Cross 2011-01-24 20:26 ` Mark Brown 2011-01-24 20:26 ` Mark Brown 2011-01-24 20:52 ` Colin Cross 2011-01-24 20:52 ` Colin Cross 2011-01-24 21:08 ` Mark Brown 2011-01-24 21:08 ` Mark Brown 2011-01-24 21:24 ` Colin Cross 2011-01-24 21:24 ` Colin Cross 2011-01-25 4:26 ` Kyungmin Park 2011-01-25 4:26 ` Kyungmin Park 2011-01-24 2:01 ` [PATCH v2 21/28] ARM: tegra: Allow overriding arch_reset Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 22/28] ARM: tegra: dma: Fix critical data corruption bugs Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 23/28] ARM: tegra: add tegra_defconfig Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 24/28] ARM: tegra: Use writel_relaxed in tegra_init_cache Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 25/28] ARM: tegra: suspend: Save protected aperture across LP0 Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 26/28] ARM: tegra: suspend: protect suspend functions with CONFIG_PM Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 27/28] ARM: tegra: enable emc clock updates after lp0 Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 2:01 ` [PATCH v2 28/28] ARM: tegra: clock: Add forward reference to struct clk Colin Cross 2011-01-24 2:01 ` Colin Cross 2011-01-24 10:26 ` Russell King - ARM Linux 2011-01-24 10:26 ` Russell King - ARM Linux 2011-01-25 1:23 ` Colin Cross 2011-01-25 1:23 ` Colin Cross 2011-01-26 3:19 ` Grant Likely 2011-01-26 3:19 ` Grant Likely 2011-01-26 3:21 ` Colin Cross 2011-01-26 3:21 ` Colin Cross 2011-01-26 4:16 ` Grant Likely 2011-01-26 4:16 ` Grant Likely
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20110204234331.GF8732@n2100.arm.linux.org.uk \ --to=linux@arm.linux.org.uk \ --cc=Catalin.Marinas@arm.com \ --cc=ccross@android.com \ --cc=konkers@android.com \ --cc=linus.walleij@stericsson.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-tegra@vger.kernel.org \ --cc=olof@lixom.net \ --cc=santosh.shilimkar@ti.com \ --cc=tony@atomide.com \ --cc=will.deacon@arm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.