linux-kernel - RE: [PATCH v2 6/6] Input: snvs_pwrkey - only IRQ

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Date:   Wed, 26 Feb 2020 01:15:23 +0000
From:   Robin Gong <yibin.gong@....com>
To:     André Draszik <git@...red.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Horia Geanta <horia.geanta@....com>,
        Aymen Sghaier <aymen.sghaier@....com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Anson Huang <anson.huang@....com>,
        "linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-input@...r.kernel.org" <linux-input@...r.kernel.org>
Subject: RE: [PATCH v2 6/6] Input: snvs_pwrkey - only IRQ_HANDLED for our own
 events

On 2020/02/26 André Draszik <git@...red.net> wrote: 
> The snvs_pwrkey shares the SNVS LPSR status register with the snvs_rtc.
> 
> This driver here should only return IRQ_HANDLED if the status register
> indicates that the event we're handling in the irq handler was genuinely
> intended for this driver. Otheriwse the interrupt subsystem will assume the
> interrupt was handled successfully even though it wasn't at all.
> 
> Signed-off-by: André Draszik <git@...red.net>
> Cc: "Horia Geantă" <horia.geanta@....com>
> Cc: Aymen Sghaier <aymen.sghaier@....com>
> Cc: Herbert Xu <herbert@...dor.apana.org.au>
> Cc: "David S. Miller" <davem@...emloft.net>
> Cc: Rob Herring <robh+dt@...nel.org>
> Cc: Mark Rutland <mark.rutland@....com>
> Cc: Shawn Guo <shawnguo@...nel.org>
> Cc: Sascha Hauer <s.hauer@...gutronix.de>
> Cc: Pengutronix Kernel Team <kernel@...gutronix.de>
> Cc: Fabio Estevam <festevam@...il.com>
> Cc: NXP Linux Team <linux-imx@....com>
> Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>
> Cc: Anson Huang <Anson.Huang@....com>
> Cc: Robin Gong <yibin.gong@....com>
> Cc: linux-crypto@...r.kernel.org
> Cc: devicetree@...r.kernel.org
> Cc: linux-arm-kernel@...ts.infradead.org
> Cc: linux-input@...r.kernel.org
> 
> ---
> v2:
> * no changes
> ---
>  drivers/input/keyboard/snvs_pwrkey.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/keyboard/snvs_pwrkey.c
> b/drivers/input/keyboard/snvs_pwrkey.c
> index 382d2ae82c9b..980867886b34 100644
> --- a/drivers/input/keyboard/snvs_pwrkey.c
> +++ b/drivers/input/keyboard/snvs_pwrkey.c
> @@ -82,7 +82,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void
> *dev_id)
>  	clk_enable(pdata->clk);
> 
>  	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
> -	if (lp_status & SNVS_LPSR_SPO) {
> +	lp_status &= SNVS_LPSR_SPO;
> +
> +	if (lp_status) {
>  		if (pdata->minor_rev == 0) {
>  			/*
>  			 * The first generation i.MX[6|7] SoCs only send an @@ -98,14
> +100,14 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void
> *dev_id)
>  			mod_timer(&pdata->check_timer,
>  			          jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
>  		}
> -	}
> 
> -	/* clear SPO status */
> -	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
> +		/* clear SPO status */
> +		regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
But irq storm will come in once there is other interrupt triggered as unexpected,
although I never met it before. Could we drop this patch now? Others are ok for me.

Reviewed-by: Robin Gong <yibin.gong@nxp>
> +	}
> 
>  	clk_disable(pdata->clk);
> 
> -	return IRQ_HANDLED;
> +	return lp_status ? IRQ_HANDLED : IRQ_NONE;
>  }
> 
>  static void imx_snvs_pwrkey_act(void *pdata)
> --
> 2.23.0.rc1