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Message-ID: <3ec20339-b176-4d39-8cbe-4577a782aeec@collabora.com>
Date: Tue, 12 Mar 2024 15:41:46 +0100
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Subject: Re: [PATCH v4] clk: mediatek: Do a runtime PM get on controllers
 during probe
Content-Language: en-US
To: Pin-yen Lin <treapking@chromium.org>,
 Michael Turquette <mturquette@baylibre.com>, Stephen Boyd
 <sboyd@kernel.org>, Matthias Brugger <matthias.bgg@gmail.com>
Cc: Chen-Yu Tsai <wenst@chromium.org>, linux-clk@vger.kernel.org,
 linux-kernel@vger.kernel.org, Weiyi Lu <weiyi.lu@mediatek.com>,
 linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org,
 Bosi Zhang <u201911157@hust.edu.cn>, Nicolas Boichat
 <drinkcat@chromium.org>, =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?=
 <u.kleine-koenig@pengutronix.de>
References: <20240312115249.3341654-1-treapking@chromium.org>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20240312115249.3341654-1-treapking@chromium.org>
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Il 12/03/24 12:51, Pin-yen Lin ha scritto:
> mt8183-mfgcfg has a mutual dependency with genpd during the probing
> stage, which leads to a deadlock in the following call stack:
> 
> CPU0:  genpd_lock --> clk_prepare_lock
> genpd_power_off_work_fn()
>   genpd_lock()
>   generic_pm_domain::power_off()
>      clk_unprepare()
>        clk_prepare_lock()
> 
> CPU1: clk_prepare_lock --> genpd_lock
> clk_register()
>    __clk_core_init()
>      clk_prepare_lock()
>      clk_pm_runtime_get()
>        genpd_lock()
> 
> Do a runtime PM get at the probe function to make sure clk_register()
> won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg,
> do this on all mediatek clock controller probings because we don't
> believe this would cause any regression.
> 
> Verified on MT8183 and MT8192 Chromebooks.
> 
> Fixes: acddfc2c261b ("clk: mediatek: Add MT8183 clock support")
> Signed-off-by: Pin-yen Lin <treapking@chromium.org>
> 

MT8195 Cherry Tomato - no issues as well.

Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>