From: Anup Patel <apatel@ventanamicro.com>
To: Sudeep Holla <sudeep.holla@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Jones <ajones@ventanamicro.com>,
Atish Patra <atishp@atishpatra.org>,
Samuel Holland <samuel@sholland.org>,
Anup Patel <anup@brainfault.org>,
devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: riscv: Add optional DT property riscv,timer-can-wake-cpu
Date: Wed, 27 Jul 2022 17:59:59 +0530 [thread overview]
Message-ID: <CAK9=C2UFgZv5T433S6EVVa+4V2Uaffg6Xq1e2zLKbdFVFYhf0Q@mail.gmail.com> (raw)
In-Reply-To: <20220727121838.tpy55twdkuasjab7@bogus>
On Wed, Jul 27, 2022 at 5:48 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Wed, Jul 27, 2022 at 05:13:01PM +0530, Anup Patel wrote:
> > We add an optional DT property riscv,timer-can-wake-cpu which if present
> > in CPU DT node then CPU timer is always powered-on and never loses context.
> >
>
> I don't have much idea on idle states on RISC-V but associating this
> property in just CPU node seems like not so good idea.
>
> This will be applicable for all CPU idle states which means you
> can't use this even if one of the deepest idle state switches off
> the timer.
>
> We have local-timer-stop in each idle states node. IIRC RISC-V uses the
> binding which is now not arm specific[0] and IIRC you moved the binding
> yourself. Any reason why not can't be used and any specific reason for
> needing this extra property.
Indeed, the "local-timer-stop" property should be used. I guess,
Allwinner D1 should use this property in idle state and we should
not unconditionally set CLOCK_EVT_FEAT_C3STOP in the timer
driver.
@Samuel Holland Can you confirm that the "local-timer-stop" property
works for Allwinner D1 ? If yes, then please send a patch to remove
CLOCK_EVT_FEAT_C3STOP from timer driver.
Regards,
Anup
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next prev parent reply other threads:[~2022-07-27 12:30 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-27 11:43 [PATCH v2 0/2] Improve CLOCK_EVT_FEAT_C3STOP feature setting Anup Patel
2022-07-27 11:43 ` [PATCH v2 1/2] dt-bindings: riscv: Add optional DT property riscv,timer-can-wake-cpu Anup Patel
2022-07-27 12:07 ` Krzysztof Kozlowski
2022-07-27 12:21 ` Anup Patel
2022-07-27 12:35 ` Krzysztof Kozlowski
2022-07-27 13:34 ` Anup Patel
2022-11-22 14:57 ` Conor Dooley
2022-11-23 5:43 ` Samuel Holland
2022-11-23 11:49 ` Conor Dooley
2022-11-23 13:46 ` Conor Dooley
2022-11-23 15:46 ` Anup Patel
2022-11-23 17:59 ` Conor Dooley
2022-07-27 12:45 ` Sudeep Holla
2022-07-27 13:19 ` Anup Patel
2022-07-27 13:45 ` Anup Patel
2022-07-27 15:26 ` Sudeep Holla
2022-07-27 12:18 ` Sudeep Holla
2022-07-27 12:29 ` Anup Patel [this message]
2022-07-27 11:43 ` [PATCH v2 2/2] clocksource: timer-riscv: Set CLOCK_EVT_FEAT_C3STOP based on DT property Anup Patel
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