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

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.

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
+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.

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.



Cheers,
Andre'

 

quoted

 }

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