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Date:   Thu, 30 Sep 2021 21:40:58 +0200
From:   Markus Schneider-Pargmann <msp@baylibre.com>
To:     Sean Wang <sean.wang@mediatek.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Matt Mackall <mpm@selenic.com>
Cc:     linux-mediatek@lists.infradead.org, linux-crypto@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] hwrng: mediatek - Force runtime pm ops for sleep ops
Message-ID: <20210930194058.oe5vlqlelilekdde@blmsp>
References: <20210930191242.2542315-1-msp@baylibre.com>
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In-Reply-To: <20210930191242.2542315-1-msp@baylibre.com>
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Hi,

On Thu, Sep 30, 2021 at 09:12:42PM +0200, Markus Schneider-Pargmann wrote:
> Currently mtk_rng_runtime_suspend/resume is called for both runtime pm
> and system sleep operations.
> 
> This is wrong as these should only be runtime ops as the name already
> suggests. Currently freezing the system will lead to a call to
> mtk_rng_runtime_suspend even if the device currently isn't active. This
> leads to a clock warning because it is disabled/unprepared although it
> isn't enabled/prepared currently.
> 
> This patch fixes this by only setting the runtime pm ops and forces to
> call the runtime pm ops from the system sleep ops as well if active but
> not otherwise.
> 
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>

Fixes: 81d2b34508c6 (hwrng: mtk - add runtime PM support)

Sorry, forgot to add this line in the commit message. I can add it for
the next version.

Best,
Markus

> ---
>  drivers/char/hw_random/mtk-rng.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/hw_random/mtk-rng.c b/drivers/char/hw_random/mtk-rng.c
> index 8ad7b515a51b..6c00ea008555 100644
> --- a/drivers/char/hw_random/mtk-rng.c
> +++ b/drivers/char/hw_random/mtk-rng.c
> @@ -166,8 +166,13 @@ static int mtk_rng_runtime_resume(struct device *dev)
>  	return mtk_rng_init(&priv->rng);
>  }
>  
> -static UNIVERSAL_DEV_PM_OPS(mtk_rng_pm_ops, mtk_rng_runtime_suspend,
> -			    mtk_rng_runtime_resume, NULL);
> +static const struct dev_pm_ops mtk_rng_pm_ops = {
> +	SET_RUNTIME_PM_OPS(mtk_rng_runtime_suspend,
> +			   mtk_rng_runtime_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
> +};
> +
>  #define MTK_RNG_PM_OPS (&mtk_rng_pm_ops)
>  #else	/* CONFIG_PM */
>  #define MTK_RNG_PM_OPS NULL
> -- 
> 2.33.0
>