[PATCH AUTOSEL 5.7 008/388] iio: pressure: bmp280: Tolerate IRQ before registering

Sasha Levin
2020-06-18T02:53:12Z

From: Andy Shevchenko <andriy.shevchenko@linux.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@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.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 29c209cc1108..2540e7c2358c 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -713,7 +713,7 @@ 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)
@@ -969,6 +969,9 @@ 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