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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Krzysztof Kozlowski <krzk@kernel.org>,
        Sebastian Reichel <sebastian.reichel@collabora.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 268/315] power: supply: max17042: Do not enforce (incorrect) interrupt trigger type
Date:   Mon, 19 Jul 2021 16:52:37 +0200
Message-Id: <20210719144952.236851829@linuxfoundation.org>
In-Reply-To: <20210719144942.861561397@linuxfoundation.org>
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From: Krzysztof Kozlowski <krzk@kernel.org>

[ Upstream commit 7fbf6b731bca347700e460d94b130f9d734b33e9 ]

Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 17047/77693 datasheets describe the interrupt line as active
low with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races.  With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/max17042_battery.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index 9c7eaaeda343..911d42366ef1 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -1051,7 +1051,7 @@ static int max17042_probe(struct i2c_client *client,
 	}
 
 	if (client->irq) {
-		unsigned int flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
+		unsigned int flags = IRQF_ONESHOT;
 
 		/*
 		 * On ACPI systems the IRQ may be handled by ACPI-event code,
-- 
2.30.2