linux-kernel - Re: [PATCH] ARM: at91: pm: set soc_pm.data.mode in at91_pm_secure

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Date:   Mon, 23 Oct 2023 09:01:32 +0300
From:   claudiu beznea <claudiu.beznea@...on.dev>
To:     thomas.perrot@...tlin.com, Russell King <linux@...linux.org.uk>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        clement.leger@...tlin.com
Subject: Re: [PATCH] ARM: at91: pm: set soc_pm.data.mode in
 at91_pm_secure_init()

Hi, Thomas,

On 20.10.2023 16:02, thomas.perrot@...tlin.com wrote:
> From: Thomas Perrot <thomas.perrot@...tlin.com>
> 
> In non secure mode, soc_pm.data.mode is set when entering pm in
> at91_pm_begin(). This value is used (not only) to determine if the system
> is going into slow clock mode (at91_suspend_entering_slow_clock()). This
> function is called from various drivers to check this and act accordingly.
> If not set, the driver might enter an incorrect suspend mode. When using
> secure suspend mode, at91_pm_begin() is not called and thus
> soc_pm.data.mode is not set. Since when using secure suspend, only one
> suspend mode is supported, set this value directly in
> at91_pm_secure_init().
> 
> Signed-off-by: Clément Léger <clement.leger@...tlin.com>
> Signed-off-by: Thomas Perrot <thomas.perrot@...tlin.com>
> ---
>  arch/arm/mach-at91/pm.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
> index 1a26af0fabc7..345b91dc6627 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -1103,6 +1103,7 @@ static void __init at91_pm_secure_init(void)
>  	if (res.a0 == 0) {
>  		pr_info("AT91: Secure PM: suspend mode set to %s\n",
>  			pm_modes[suspend_mode].pattern);
> +		soc_pm.data.mode = suspend_mode;
>  		return;
>  	}
>  
> @@ -1112,6 +1113,7 @@ static void __init at91_pm_secure_init(void)
>  	res = sam_smccc_call(SAMA5_SMC_SIP_GET_SUSPEND_MODE, 0, 0);
>  	if (res.a0 == 0) {
>  		pr_warn("AT91: Secure PM: failed to get default mode\n");
> +		soc_pm.data.mode = -1;

As this variable's type is unsigned int setting it -1 will make
at91_suspend_entering_slow_clock() return true all the time. Is this what
you intend?

Thank you,
Claudiu Beznea

>  		return;
>  	}
>  
> @@ -1119,6 +1121,7 @@ static void __init at91_pm_secure_init(void)
>  		pm_modes[suspend_mode].pattern);
>  
>  	soc_pm.data.suspend_mode = res.a1;
> +	soc_pm.data.mode = soc_pm.data.suspend_mode;
>  }
>  static const struct of_device_id atmel_shdwc_ids[] = {
>  	{ .compatible = "atmel,sama5d2-shdwc" },