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Message-Id: <20200618011631.604574-6-sashal@kernel.org>
Date:   Wed, 17 Jun 2020 21:12:11 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        Sasha Levin <sashal@...nel.org>, linux-iio@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 006/266] iio: pressure: bmp280: Tolerate IRQ before registering
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
[ Upstream commit 97b31a6f5fb95b1ec6575b78a7240baddba34384 ]
With DEBUG_SHIRQ enabled we have a kernel crash
[  116.482696] BUG: kernel NULL pointer dereference, address: 0000000000000000
...
[  116.606571] Call Trace:
[  116.609023]  <IRQ>
[  116.611047]  complete+0x34/0x50
[  116.614206]  bmp085_eoc_irq+0x9/0x10 [bmp280]
because DEBUG_SHIRQ mechanism fires an IRQ before registration and drivers
ought to be able to handle an interrupt happening before request_irq() returns.
Fixes: aae953949651 ("iio: pressure: bmp280: add support for BMP085 EOC interrupt")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Acked-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/iio/pressure/bmp280-core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 8d0f15f27dc5..084a1d56cc2f 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -706,7 +706,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 	unsigned int ctrl;
 
 	if (data->use_eoc)
-		init_completion(&data->done);
+		reinit_completion(&data->done);
 
 	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
 	if (ret)
@@ -962,6 +962,9 @@ static int bmp085_fetch_eoc_irq(struct device *dev,
 			"trying to enforce it\n");
 		irq_trig = IRQF_TRIGGER_RISING;
 	}
+
+	init_completion(&data->done);
+
 	ret = devm_request_threaded_irq(dev,
 			irq,
 			bmp085_eoc_irq,
-- 
2.25.1
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