On 2020/02/27 André Draszik [off-list ref] wrote:

On Wed, 2020-02-26 at 01:15 +0000, Robin Gong wrote:

quoted

On 2020/02/26 André Draszik [off-list ref] wrote:

quoted

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.

quoted

quoted

Signed-off-by: André Draszik <redacted>
Cc: "Horia Geantă" <horia.geanta@nxp.com>
Cc: Aymen Sghaier <redacted>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <redacted>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Anson Huang <redacted>
Cc: Robin Gong <redacted>
Cc: linux-crypto@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-input@vger.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

quoted

quoted

+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.

I don't have strong feelings about this patch, but this bit merely changes
behaviour to clear SP0 if SP0 was in fact != 0 in the first place, whereas before
SP0 was always cleared, even if it was == 0 anyway. Seems more logical in my
eyes.

Seems we care something never happen:) I'm okay if you really want to do that.

quoted

Reviewed-by: Robin Gong <redacted>

quoted

+	}

 	clk_disable(pdata->clk);

-	return IRQ_HANDLED;
+	return lp_status ? IRQ_HANDLED : IRQ_NONE;

If you're talking about this part, the rtc-snvs driver does the same in its
interrupt handler.
In other words, this driver here could prevent the rtc-snvs driver from seeing its
events

But rtc driver has another interrupt number, and snvs_pwrkey driver just touch SPO bit
as below:
regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
So I don't think it could impact rtc-snvs driver. But you remind me rtc-snvs driver may clear SPO status, because lpsr is read from SNVS_LPSR which may SPO has already been set.
regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
I'll send a patch for fix that potential issue. Besides, if you really want to follow rtc driver please initialize lp_status with 0.  

Cheers,
Andre'

quoted

quoted

 }

 static void imx_snvs_pwrkey_act(void *pdata)
--
2.23.0.rc1

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