RE: [PATCH v2 6/6] Input: snvs_pwrkey - only IRQ_HANDLED for our own events

[Robin Gong]

On 2020/02/26 Andrà Draszik <git@xxxxxxxxxx> 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: Andrà Draszik <git@xxxxxxxxxx>
> Cc: "Horia GeantÄ" <horia.geanta@xxxxxxx>
> Cc: Aymen Sghaier <aymen.sghaier@xxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: NXP Linux Team <linux-imx@xxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Anson Huang <Anson.Huang@xxxxxxx>
> Cc: Robin Gong <yibin.gong@xxxxxxx>
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-input@xxxxxxxxxxxxxxx
> 
> ---
> 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