[RFT PATCH 4/9] usb: typec: tipd: Add short-circuit for no irqs

From: Sven Peter <sven@svenpeter.dev>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: "Sven Peter" <sven@svenpeter.dev>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Guido Günther" <agx@sigxcpu.org>,
	"Bryan O'Donoghue" <bryan.odonoghue@linaro.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Hector Martin" <marcan@marcan.st>,
	"Mohamed Mediouni" <mohamed.mediouni@caramail.com>,
	"Stan Skowronek" <stan@corellium.com>,
	"Mark Kettenis" <mark.kettenis@xs4all.nl>,
	"Alexander Graf" <graf@amazon.com>,
	"Alyssa Rosenzweig" <alyssa@rosenzweig.io>
Subject: [RFT PATCH 4/9] usb: typec: tipd: Add short-circuit for no irqs
Date: Sat, 18 Sep 2021 14:09:29 +0200	[thread overview]
Message-ID: <20210918120934.28252-5-sven@svenpeter.dev> (raw)
In-Reply-To: <20210918120934.28252-1-sven@svenpeter.dev>

If no interrupts are set in IntEventX directly skip to the end of the
interrupt handler and return IRQ_NONE instead of IRQ_HANDLED.
This possibly allows to detect spurious interrupts if the i2c bus is fast
enough.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/usb/typec/tipd/core.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index c2c399722c37..4a6d66250fef 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -434,6 +434,8 @@ static irqreturn_t tps6598x_interrupt(int irq, void *data)
 	trace_tps6598x_irq(event1, event2);
 
 	event = event1 | event2;
+	if (!event)
+		goto err_unlock;
 
 	ret = tps6598x_read32(tps, TPS_REG_STATUS, &status);
 	if (ret) {
@@ -481,7 +483,9 @@ static irqreturn_t tps6598x_interrupt(int irq, void *data)
 err_unlock:
 	mutex_unlock(&tps->lock);
 
-	return IRQ_HANDLED;
+	if (event)
+		return IRQ_HANDLED;
+	return IRQ_NONE;
 }
 
 static int tps6598x_check_mode(struct tps6598x *tps)
-- 
2.25.1

