linux-kernel - Re: [PATCH v2] ARM: imx6: mask all interrupts before calling stby-poweroff sequence

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Date:   Wed, 22 Sep 2021 10:37:40 +0800
From:   Shawn Guo <shawnguo@...nel.org>
To:     Oleksij Rempel <o.rempel@...gutronix.de>
Cc:     Sascha Hauer <s.hauer@...gutronix.de>, kernel@...gutronix.de,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Fabio Estevam <festevam@...il.com>, linux-imx@....com
Subject: Re: [PATCH v2] ARM: imx6: mask all interrupts before calling
 stby-poweroff sequence

On Tue, Aug 17, 2021 at 02:25:00PM +0200, Oleksij Rempel wrote:
> Any pending interrupt can prevent entering standby based power off state.
> To avoid it, mask all interrupts.
> 
> Fixes: 8148d2136002 ("ARM: imx6: register pm_power_off handler if "fsl,pmic-stby-poweroff" is set")
> Signed-off-by: Oleksij Rempel <o.rempel@...gutronix.de>
> ---
>  arch/arm/mach-imx/pm-imx6.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
> index 9244437cb1b9..63887ade411a 100644
> --- a/arch/arm/mach-imx/pm-imx6.c
> +++ b/arch/arm/mach-imx/pm-imx6.c
> @@ -59,8 +59,11 @@
>  #define MX6Q_SUSPEND_OCRAM_SIZE		0x1000
>  #define MX6_MAX_MMDC_IO_NUM		33
>  
> +#define GIC_DIST_ENABLE_CLEAR		0x180
> +
>  static void __iomem *ccm_base;
>  static void __iomem *suspend_ocram_base;
> +static void __iomem *gic_raw_dist_base;
>  static void (*imx6_suspend_in_ocram_fn)(void __iomem *ocram_vbase);
>  
>  /*
> @@ -592,6 +595,7 @@ static int __init imx6q_suspend_init(const struct imx6_pm_socdata *socdata)
>  static void __init imx6_pm_common_init(const struct imx6_pm_socdata
>  					*socdata)
>  {
> +	struct device_node *np;
>  	struct regmap *gpr;
>  	int ret;
>  
> @@ -615,10 +619,29 @@ static void __init imx6_pm_common_init(const struct imx6_pm_socdata
>  	if (!IS_ERR(gpr))
>  		regmap_update_bits(gpr, IOMUXC_GPR1, IMX6Q_GPR1_GINT,
>  				   IMX6Q_GPR1_GINT);
> +
> +	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
> +	gic_raw_dist_base = of_iomap(np, 0);
> +}
> +
> +static void imx_gic_mask_all(void)
> +{
> +	int i;
> +
> +	if (WARN_ON(!gic_raw_dist_base))
> +		return;
> +
> +	for (i = 0; i < 4; i++)
> +		writel_relaxed(~0, gic_raw_dist_base + GIC_DIST_ENABLE_CLEAR + 4 * i);

Is it possible to have a helper function in GIC driver, that we can
simply call into?

Shawn

>  }
>  
>  static void imx6_pm_stby_poweroff(void)
>  {
> +	/*
> +	 * A pending interrupt can prevent power off signal to be activated.
> +	 * So, mask all interrupts to avoid it.
> +	 */
> +	imx_gic_mask_all();
>  	imx6_set_lpm(STOP_POWER_OFF);
>  	imx6q_suspend_finish(0);
>  
> -- 
> 2.30.2
>