From: Rob Herring <robh@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>,
Phil Edworthy <phil.edworthy@renesas.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Biju Das <biju.das.jz@bp.renesas.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Marc Zyngier <maz@kernel.org>,
devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v3 04/12] dt-bindings: timer: arm,arch_timer: Add optional clock and reset
Date: Wed, 4 May 2022 17:33:05 -0500 [thread overview]
Message-ID: <YnL/IbciNHLhoNOZ@robh.at.kernel.org> (raw)
In-Reply-To: <YnEqH+gzlfv96opc@lakrids>
On Tue, May 03, 2022 at 02:11:59PM +0100, Mark Rutland wrote:
> Hi Phil,
>
> This is the only patch from this series that I've received, and judging
> by the CC list this hasn't gone to either LKML or LAKML, so I'm missing
> the surrounding context for this.
>
> Looking on lore, this is part of:
>
> https://lore.kernel.org/linux-devicetree/20220503115557.53370-1-phil.edworthy@renesas.com/T/#t
>
> ... which is adding support for an arm64 SoC.
>
> On Tue, May 03, 2022 at 12:55:49PM +0100, Phil Edworthy wrote:
> > Some SoCs use a gated clock for the timer and the means to reset the timer.
> > Hence add these as optional.
>
> The clock feeding the architected timer is supposed to be in an
> always-on clock domain, and is supopsed to be enabled before running any
> Normal World software.
>
> The arm64 kernel *requires* that this is enabled prior to entry. If the
> kernel ever has to touch either the clock or reset, then there are
> phases where the counter will not function correctly, which is simply
> broken.
>
> Given that, I do not think this should be in the DT, and instead the
> clock should be marked as critical in the provider node (and the reset
> should never be touched).
That is not yet an accepted DT property, but is currently on the list
for review[1]. If that's something people need, chime in. More than 1
person needing something is always better.
Rob
[1] https://lore.kernel.org/all/20220428110107.149524-1-marex@denx.de/
next prev parent reply other threads:[~2022-05-04 22:33 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-03 11:55 [PATCH v3 00/12] Add new Renesas RZ/V2M SoC and Renesas RZ/V2M EVK support Phil Edworthy
2022-05-03 11:55 ` [PATCH v3 01/12] dt-bindings: serial: renesas,em-uart: Add RZ/V2M clock to access the registers Phil Edworthy
2022-05-04 8:06 ` Geert Uytterhoeven
2022-05-04 8:13 ` Phil Edworthy
2022-05-03 11:55 ` [PATCH v3 02/12] dt-bindings: clock: Add r9a09g011 CPG Clock Definitions Phil Edworthy
2022-05-04 8:43 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 03/12] dt-bindings: clock: renesas,rzg2l: Document RZ/V2M SoC Phil Edworthy
2022-05-04 8:43 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 04/12] dt-bindings: timer: arm,arch_timer: Add optional clock and reset Phil Edworthy
2022-05-03 13:11 ` Mark Rutland
2022-05-04 22:33 ` Rob Herring [this message]
2022-05-05 6:42 ` Geert Uytterhoeven
2022-05-03 13:12 ` Marc Zyngier
2022-05-03 14:22 ` Geert Uytterhoeven
2022-05-03 14:55 ` Mark Rutland
2022-05-03 15:56 ` Marc Zyngier
2022-05-04 9:05 ` Phil Edworthy
2022-05-03 11:55 ` [PATCH v3 05/12] clk: renesas: rzg2l: Move the DEF_MUX array size calc into the macro Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 06/12] clk: renesas: rzg2l: Add read only versions of the clk macros Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 07/12] clk: renesas: rzg2l: Set HIWORD mask for all mux and dividers Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 08/12] clk: renesas: rzg2l: Make use of CLK_MON registers optional Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 09/12] clk: renesas: rzg2l: Add support for RZ/V2M reset monitor reg Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 10/12] clk: renesas: Add RZ/V2M support using the rzg2l driver Phil Edworthy
2022-05-04 8:44 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 11/12] arm64: dts: renesas: Add initial DTSI for RZ/V2M SoC Phil Edworthy
2022-05-04 8:47 ` Geert Uytterhoeven
2022-05-03 11:55 ` [PATCH v3 12/12] arm64: dts: renesas: Add initial device tree for RZ/V2M EVK Phil Edworthy
2022-05-04 8:51 ` Geert Uytterhoeven
2022-05-04 9:00 ` Phil Edworthy
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