From: Lina Iyer <lina.iyer@linaro.org> To: Brendan Jackman <brendan.jackman@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com>, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ulf.hansson@linaro.org, khilman@kernel.org, rjw@rjwysocki.net, andy.gross@linaro.org, sboyd@codeaurora.org, linux-arm-msm@vger.kernel.org, Axel Haslam <ahaslam+renesas@baylibre.com>, devicetree@vger.kernel.org, Marc Titinger <mtitinger+renesas@baylibre.com>, Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>, Juri Lelli <Juri.Lelli@arm.com> Subject: Re: [PATCH v3 02/15] dt/bindings: Update binding for PM domain idle states Date: Mon, 15 Aug 2016 10:06:13 -0600 [thread overview] Message-ID: <20160815160613.GD1401@linaro.org> (raw) In-Reply-To: <20160812123516.GA24194@brendan-thinkstation> On Fri, Aug 12 2016 at 06:35 -0600, Brendan Jackman wrote: >> >In general whatever binding we come up must not just address OS >> >coordinated mode. Also I was thinking to have better coverage in >> >the description by having a bit more complex system like: >> > >> >cluster0 >> > CLUSTER_RET(Retention) >> > CLUSTER_PG(Power Gate) >> > core0 >> > CORE_RET >> > CORE_PG >> > core1 >> > CORE_RET >> > CORE_PG >> > >> >cluster1 >> > CLUSTER_RET >> > CLUSTER_PG >> > core0 >> > CORE_RET >> > CORE_PG >> > core1 >> > CORE_RET >> > CORE_PG >> > >> >Platform Co-ordinate supports the following states and we should >> >be able to determine that from the binding: >> > >> >CORE_RET >> >CORE_PG >> >CORE_RET + CLUSTER_RET >> >> The problem that we have to sove here is knowing that CORE_RET + >> CLUSTER_PG (hypothetically) an invalid combination. Kevin and >> I debated it in the earlier RFC and we dont have a good way to solve >> this generically for all devices. >> > > >This is interesting. I had been working on the assumption that a parent >power domain cannot enter any idle state until its children were all in >their deepest idle state. I now realise that it's easy to imagine >platforms where this isn't the case. > >However, I don't understand how your current bindings solve this issue >and why using domain-power-states for all states (i.e. ignoring >cpu-idle-states and putting CPU idle states in the domain-idle-states of >a per-CPU power domain - I believe this is what Sudeep is suggesting) >makes it any more difficult. > You are right, my current bindings don't solve it. I imagined one would solve it by writing their own CPU PM Domain governor. In the context of platform coordinated, we dont have a choice in Linux. May be the firmware can assert that intelligence in not choosing those states. So, we may have states added to cpuidle that are invalid and never get chosen by the firmware. I am not sure, but may be that is acceptable. >Could you link to this previous discussion you mentioned? I'm having >trouble finding it (R.I.P Gmane). > Sigh. So hard to search. Let me see where it is, if it in mail or IRC communication. Thanks, Lina >> >CORE_PG + CLUSTER_RET >> >CORE_PG + CLUSTER_PG >> > > >Cheers, >Brendan
WARNING: multiple messages have this Message-ID (diff)
From: lina.iyer@linaro.org (Lina Iyer) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 02/15] dt/bindings: Update binding for PM domain idle states Date: Mon, 15 Aug 2016 10:06:13 -0600 [thread overview] Message-ID: <20160815160613.GD1401@linaro.org> (raw) In-Reply-To: <20160812123516.GA24194@brendan-thinkstation> On Fri, Aug 12 2016 at 06:35 -0600, Brendan Jackman wrote: >> >In general whatever binding we come up must not just address OS >> >coordinated mode. Also I was thinking to have better coverage in >> >the description by having a bit more complex system like: >> > >> >cluster0 >> > CLUSTER_RET(Retention) >> > CLUSTER_PG(Power Gate) >> > core0 >> > CORE_RET >> > CORE_PG >> > core1 >> > CORE_RET >> > CORE_PG >> > >> >cluster1 >> > CLUSTER_RET >> > CLUSTER_PG >> > core0 >> > CORE_RET >> > CORE_PG >> > core1 >> > CORE_RET >> > CORE_PG >> > >> >Platform Co-ordinate supports the following states and we should >> >be able to determine that from the binding: >> > >> >CORE_RET >> >CORE_PG >> >CORE_RET + CLUSTER_RET >> >> The problem that we have to sove here is knowing that CORE_RET + >> CLUSTER_PG (hypothetically) an invalid combination. Kevin and >> I debated it in the earlier RFC and we dont have a good way to solve >> this generically for all devices. >> > > >This is interesting. I had been working on the assumption that a parent >power domain cannot enter any idle state until its children were all in >their deepest idle state. I now realise that it's easy to imagine >platforms where this isn't the case. > >However, I don't understand how your current bindings solve this issue >and why using domain-power-states for all states (i.e. ignoring >cpu-idle-states and putting CPU idle states in the domain-idle-states of >a per-CPU power domain - I believe this is what Sudeep is suggesting) >makes it any more difficult. > You are right, my current bindings don't solve it. I imagined one would solve it by writing their own CPU PM Domain governor. In the context of platform coordinated, we dont have a choice in Linux. May be the firmware can assert that intelligence in not choosing those states. So, we may have states added to cpuidle that are invalid and never get chosen by the firmware. I am not sure, but may be that is acceptable. >Could you link to this previous discussion you mentioned? I'm having >trouble finding it (R.I.P Gmane). > Sigh. So hard to search. Let me see where it is, if it in mail or IRC communication. Thanks, Lina >> >CORE_PG + CLUSTER_RET >> >CORE_PG + CLUSTER_PG >> > > >Cheers, >Brendan
next prev parent reply other threads:[~2016-08-15 16:06 UTC|newest] Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-08-04 23:04 [PATCH v3 00/15] PM: SoC idle support using PM domains Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 01/15] PM / Domains: Allow domain power states to be read from DT Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 02/15] dt/bindings: Update binding for PM domain idle states Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-09 23:55 ` Rob Herring 2016-08-09 23:55 ` Rob Herring 2016-08-10 15:14 ` Sudeep Holla 2016-08-10 15:14 ` Sudeep Holla 2016-08-10 16:40 ` Lina Iyer 2016-08-10 16:40 ` Lina Iyer [not found] ` <20160810164034.GA1401-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-08-10 18:09 ` Sudeep Holla 2016-08-10 18:09 ` Sudeep Holla 2016-08-10 18:13 ` Sudeep Holla 2016-08-10 18:13 ` Sudeep Holla [not found] ` <5e59874c-bbb7-270a-199c-da1ff5932554-5wv7dgnIgG8@public.gmane.org> 2016-08-11 21:10 ` Lina Iyer 2016-08-11 21:10 ` Lina Iyer [not found] ` <20160811211023.GC1401-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-08-12 9:47 ` Brendan Jackman 2016-08-12 9:47 ` Brendan Jackman 2016-08-12 10:08 ` Sudeep Holla 2016-08-12 10:08 ` Sudeep Holla 2016-08-15 16:08 ` Lina Iyer 2016-08-15 16:08 ` Lina Iyer 2016-08-15 16:14 ` Sudeep Holla 2016-08-15 16:14 ` Sudeep Holla 2016-08-15 22:40 ` Lina Iyer 2016-08-15 22:40 ` Lina Iyer [not found] ` <20160815224014.GF1401-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-08-16 8:34 ` Brendan Jackman 2016-08-16 8:34 ` Brendan Jackman 2016-08-16 8:41 ` Brendan Jackman 2016-08-16 8:41 ` Brendan Jackman 2016-08-16 9:19 ` Sudeep Holla 2016-08-16 9:19 ` Sudeep Holla 2016-08-12 12:35 ` Brendan Jackman 2016-08-12 12:35 ` Brendan Jackman 2016-08-15 16:06 ` Lina Iyer [this message] 2016-08-15 16:06 ` Lina Iyer 2016-08-19 18:10 ` Kevin Hilman 2016-08-19 18:10 ` Kevin Hilman 2016-08-24 14:07 ` Sudeep Holla 2016-08-24 14:07 ` Sudeep Holla [not found] ` <1470351902-43103-3-git-send-email-lina.iyer-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-08-24 13:48 ` [RFC 0/6] Illustration of using domain-idle-states for CPU " Brendan Jackman 2016-08-24 13:48 ` [RFC 1/6] cpuidle: Rename cpuidle_get_{cpu->dev}_driver Brendan Jackman 2016-08-24 13:48 ` [RFC 2/6] cpuidle: Add public funcion to get driver from CPU index Brendan Jackman [not found] ` <20160824134822.3591-1-brendan.jackman-5wv7dgnIgG8@public.gmane.org> 2016-08-24 13:48 ` [RFC 3/6] cpuidle: Add device_node pointer in cpuidle_state Brendan Jackman 2016-08-24 13:48 ` [RFC 6/6] arm64: dts: Add domain-idle-states for Juno r0 power domains Brendan Jackman 2016-08-24 13:48 ` [RFC 4/6] cpuidle: dt: Add support for reading states from " Brendan Jackman 2016-08-24 13:48 ` [RFC 5/6] arm64: dts: Add Juno r0 CPU power domain tree Brendan Jackman 2016-08-04 23:04 ` [PATCH v3 03/15] PM / Domains: Abstract genpd locking Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 04/15] PM / Domains: Support IRQ safe PM domains Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 05/15] PM / doc: Update device documentation for devices in " Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 06/15] PM / cpu_domains: Setup PM domains for CPUs/clusters Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 07/15] ARM: cpuidle: Add runtime PM support for CPUs Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 08/15] timer: Export next wake up of a CPU Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 09/15] PM / cpu_domains: Add PM Domain governor for CPUs Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 10/15] doc / cpu_domains: Describe CPU PM domains setup and governor Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 11/15] drivers: firmware: psci: Allow OS Initiated suspend mode Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:04 ` [PATCH v3 12/15] drivers: firmware: psci: Support cluster idle states for OS-Initiated Lina Iyer 2016-08-04 23:04 ` Lina Iyer 2016-08-04 23:05 ` [PATCH v3 13/15] dt/bindings: Add PSCI OS-Initiated PM Domains bindings Lina Iyer 2016-08-04 23:05 ` Lina Iyer 2016-08-05 14:44 ` Lina Iyer 2016-08-05 14:44 ` Lina Iyer 2016-08-04 23:05 ` [PATCH v3 14/15] ARM64: dts: Add PSCI cpuidle support for MSM8916 Lina Iyer 2016-08-04 23:05 ` Lina Iyer [not found] ` <1470351902-43103-1-git-send-email-lina.iyer-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-08-04 23:05 ` [PATCH v3 15/15] ARM64: dts: Define CPU power domain " Lina Iyer 2016-08-04 23:05 ` Lina Iyer 2016-08-10 15:27 ` Sudeep Holla 2016-08-10 15:27 ` Sudeep Holla 2016-08-10 17:35 ` Lina Iyer 2016-08-10 17:35 ` Lina Iyer 2016-08-11 9:30 ` Sudeep Holla 2016-08-11 9:30 ` Sudeep Holla
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