Re: [PATCH] Revert "firmware: arm_scmi: Add clock management to the SCMI power domain"

From: Sudeep Holla <sudeep.holla@arm.com>
To: Ulf Hansson <ulf.hansson@linaro.org>,
	Dien Pham <dien.pham.ry@renesas.com>,
	Gaku Inami <gaku.inami.xh@renesas.com>
Cc: Cristian Marussi <cristian.marussi@arm.com>,
	linux-arm-kernel@lists.infradead.org, Peng Fan <peng.fan@nxp.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Nicolas Pitre <npitre@baylibre.com>,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] Revert "firmware: arm_scmi: Add clock management to the SCMI power domain"
Date: Wed, 21 Sep 2022 16:56:34 +0100	[thread overview]
Message-ID: <20220921155634.owr5lncydsfpo7ua@bogus> (raw)
In-Reply-To: <20220919122033.86126-1-ulf.hansson@linaro.org>

Hi Dien, Gaku,

On Mon, Sep 19, 2022 at 02:20:33PM +0200, Ulf Hansson wrote:
> This reverts commit a3b884cef873 ("firmware: arm_scmi: Add clock management
> to the SCMI power domain").
> 
> Using the GENPD_FLAG_PM_CLK tells genpd to gate/ungate the consumer
> device's clock(s) during runtime suspend/resume through the PM clock API.
> More precisely, in genpd_runtime_resume() the clock(s) for the consumer
> device would become ungated prior to the driver-level ->runtime_resume()
> callbacks gets invoked.
> 
> This behaviour isn't a good fit for all platforms/drivers. For example, a
> driver may need to make some preparations of its device in its
> ->runtime_resume() callback, like calling clk_set_rate() before the
> clock(s) should be ungated. In these cases, it's easier to let the clock(s)
> to be managed solely by the driver, rather than at the PM domain level.
> 
> For these reasons, let's drop the use GENPD_FLAG_PM_CLK for the SCMI PM
> domain, as to enable it to be more easily adopted across ARM platforms.
> 
> Fixes: a3b884cef873 ("firmware: arm_scmi: Add clock management to the SCMI power domain")
> Cc: Nicolas Pitre <npitre@baylibre.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
> 
> To get some more background to $subject patch, please have a look at the
> lore-link below.
> 
> https://lore.kernel.org/all/DU0PR04MB94173B45A2CFEE3BF1BD313A88409@DU0PR04MB9417.eurprd04.prod.outlook.com/
>

If you have any objections, this is your last chance to speak up before
the original change gets reverted in the mainline with this patch.

Hi Ulf,

I don't have any other SCMI changes for v6.0 fixes or v6.1
I am fine if you are happy to take this via your tree or I can send it
to SoC team. Let me know. I will give final one or 2 days for Renesas
to get back if they really care much.

--
Regards,
Sudeep

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