linux-kernel - [PATCH 3/3] Input: snvs_pwrkey - only IRQ

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Message-Id: <20200130204516.4760-3-git@andred.net>
Date:   Thu, 30 Jan 2020 20:45:16 +0000
From:   André Draszik <git@...red.net>
To:     linux-kernel@...r.kernel.org
Cc:     André Draszik <git@...red.net>,
        Anson Huang <Anson.Huang@....com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        linux-input@...r.kernel.org
Subject: [PATCH 3/3] Input: snvs_pwrkey - only IRQ_HANDLED for our own events

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: Anson Huang <Anson.Huang@....com>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: Alessandro Zummo <a.zummo@...ertech.it>
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc: linux-input@...r.kernel.org
---
 drivers/input/keyboard/snvs_pwrkey.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
index c29711d8735c..9f51bcc5b5fd 100644
--- a/drivers/input/keyboard/snvs_pwrkey.c
+++ b/drivers/input/keyboard/snvs_pwrkey.c
@@ -80,7 +80,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 	pm_wakeup_event(input->dev.parent, 0);
 
 	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.MX6 SoCs only sends an
@@ -96,15 +98,14 @@ 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);
+		regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
+	}
 
 	if (pdata->clk)
 		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