From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
To: Chen-Yu Tsai <wenst@chromium.org>, Pin-yen Lin <treapking@chromium.org>
Cc: Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
Weiyi Lu <weiyi.lu@mediatek.com>,
linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 1/2] clk: mediatek: Introduce need_pm_runtime to mtk_clk_desc
Date: Mon, 26 Feb 2024 12:16:10 +0100 [thread overview]
Message-ID: <e0e6febf-1045-49f8-a200-8bc095b0fa50@collabora.com> (raw)
In-Reply-To: <CAGXv+5EnBt+7WrNb-QyziEaCihvjhFVf2tpzk=XyAoeELqucaw@mail.gmail.com>
Il 23/02/24 05:27, Chen-Yu Tsai ha scritto:
> On Mon, Jan 8, 2024 at 4:18 PM Pin-yen Lin <treapking@chromium.org> wrote:
>>
>> Introduce a new need_pm_runtime variable to mtk_clk_desc to indicate
>> this clock controller needs runtime PM for its operations.
>> Also do a runtime PM get on the clock controller during the
>> probing stage to workaround a possible deadlock.
>>
>> Signed-off-by: Pin-yen Lin <treapking@chromium.org>
>
> Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
>
> The patch itself looks fine.
>
> Besides the MT8183 MFG clock issues, we do actually need this for the
> MT8192 ADSP clock. Its power domain is not enabled by default.
>
...but on MT8195 the ADSP clock works - because the ADSP node exists.
This poses a question: should we make clock controllers depend on power domains,
or should we keep everything powered off (hence clocks down - no power consumption)
*unless* the user exists?
For the second one, this means that the *device* gets the power domain (adsp), and
not the clock controller (which clocks are effectively useless if there's no user).
Angelo
>> ---
>>
>> Changes in v3:
>> - Update the commit message and the comments before runtime PM call
>>
>> Changes in v2:
>> - Fix the order of error handling
>> - Update the commit message and add a comment before the runtime PM call
>>
>> drivers/clk/mediatek/clk-mtk.c | 19 +++++++++++++++++++
>> drivers/clk/mediatek/clk-mtk.h | 2 ++
>> 2 files changed, 21 insertions(+)
>>
>> diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
>> index 2e55368dc4d8..ba1d1c495bc2 100644
>> --- a/drivers/clk/mediatek/clk-mtk.c
>> +++ b/drivers/clk/mediatek/clk-mtk.c
>> @@ -13,6 +13,7 @@
>> #include <linux/of.h>
>> #include <linux/of_address.h>
>> #include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> #include <linux/slab.h>
>>
>> #include "clk-mtk.h"
>> @@ -494,6 +495,18 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
>> return IS_ERR(base) ? PTR_ERR(base) : -ENOMEM;
>> }
>>
>> +
>> + if (mcd->need_runtime_pm) {
>> + devm_pm_runtime_enable(&pdev->dev);
>> + /*
>> + * Do a pm_runtime_resume_and_get() to workaround a possible
>> + * deadlock between clk_register() and the genpd framework.
>> + */
>> + r = pm_runtime_resume_and_get(&pdev->dev);
>> + if (r)
>> + return r;
>> + }
>> +
>> /* Calculate how many clk_hw_onecell_data entries to allocate */
>> num_clks = mcd->num_clks + mcd->num_composite_clks;
>> num_clks += mcd->num_fixed_clks + mcd->num_factor_clks;
>> @@ -574,6 +587,9 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
>> goto unregister_clks;
>> }
>>
>> + if (mcd->need_runtime_pm)
>> + pm_runtime_put(&pdev->dev);
>> +
>> return r;
>>
>> unregister_clks:
>> @@ -604,6 +620,9 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
>> free_base:
>> if (mcd->shared_io && base)
>> iounmap(base);
>> +
>> + if (mcd->need_runtime_pm)
>> + pm_runtime_put(&pdev->dev);
>> return r;
>> }
>>
>> diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
>> index 22096501a60a..c17fe1c2d732 100644
>> --- a/drivers/clk/mediatek/clk-mtk.h
>> +++ b/drivers/clk/mediatek/clk-mtk.h
>> @@ -237,6 +237,8 @@ struct mtk_clk_desc {
>>
>> int (*clk_notifier_func)(struct device *dev, struct clk *clk);
>> unsigned int mfg_clk_idx;
>> +
>> + bool need_runtime_pm;
>> };
>>
>> int mtk_clk_pdev_probe(struct platform_device *pdev);
>> --
>> 2.43.0.472.g3155946c3a-goog
>>
next prev parent reply other threads:[~2024-02-26 11:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-08 8:18 [PATCH v3 1/2] clk: mediatek: Introduce need_pm_runtime to mtk_clk_desc Pin-yen Lin
2024-01-08 8:18 ` [PATCH v3 2/2] clk: mediatek: mt8183: Enable need_runtime_pm on mt8183-mfgcfg Pin-yen Lin
2024-02-23 4:43 ` Chen-Yu Tsai
2024-02-26 11:35 ` AngeloGioacchino Del Regno
2024-02-23 4:27 ` [PATCH v3 1/2] clk: mediatek: Introduce need_pm_runtime to mtk_clk_desc Chen-Yu Tsai
2024-02-26 11:16 ` AngeloGioacchino Del Regno [this message]
2024-02-29 7:17 ` Chen-Yu Tsai
2024-02-29 9:45 ` AngeloGioacchino Del Regno
2024-02-29 10:34 ` Chen-Yu Tsai
2024-02-29 10:36 ` AngeloGioacchino Del Regno
2024-03-07 11:10 ` Pin-yen Lin
2024-03-07 11:22 ` AngeloGioacchino Del Regno
2024-03-12 9:35 ` Pin-yen Lin
2024-03-12 9:45 ` AngeloGioacchino Del Regno
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