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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Jonathan Cameron <jic23@kernel.org>,
	linux-iio@vger.kernel.org, Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Linus Walleij <linus.walleij@linaro.org>
Subject: [PATCH v1 1/5] iio: pressure: bmp280: Tolerate IRQ before registering
Date: Tue, 17 Mar 2020 12:18:09 +0200	[thread overview]
Message-ID: <20200317101813.30829-1-andriy.shevchenko@linux.intel.com> (raw)

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")
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/iio/pressure/bmp280-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 29c209cc1108..5e229b95308e 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -712,8 +712,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 	unsigned int delay_us;
 	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)
@@ -969,6 +968,9 @@ 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


             reply	other threads:[~2020-03-17 10:18 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-17 10:18 Andy Shevchenko [this message]
2020-03-17 10:18 ` [PATCH v1 2/5] iio: pressure: bmp280: Use IIO_DEVICE_ATTR_RO macro Andy Shevchenko
2020-03-22 17:16   ` Jonathan Cameron
2020-03-22 21:17     ` Andy Shevchenko
2020-03-23  9:38       ` Jonathan Cameron
2020-03-17 10:18 ` [PATCH v1 3/5] iio: pressure: bmp280: Explicitly mark GPIO optional Andy Shevchenko
2020-03-17 10:18 ` [PATCH v1 4/5] iio: pressure: bmp280: Drop unneeded explicit castings Andy Shevchenko
2020-03-22 17:21   ` Jonathan Cameron
2020-03-22 21:20     ` Andy Shevchenko
2020-03-17 10:18 ` [PATCH v1 5/5] iio: pressure: bmp280: Join string literals back Andy Shevchenko
2020-03-22 17:12 ` [PATCH v1 1/5] iio: pressure: bmp280: Tolerate IRQ before registering Jonathan Cameron
2020-03-22 21:15   ` Andy Shevchenko
2020-03-23  9:40     ` Jonathan Cameron
2020-03-23 10:08       ` Andy Shevchenko

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