[PATCH AUTOSEL 4.19 006/172] iio: pressure: bmp280: Tolerate IRQ before registering

[PATCH AUTOSEL 4.19 006/172] iio: pressure: bmp280: Tolerate IRQ before registering

[Sasha Levin]

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 fe87d27779d9..d47922a1d0f3 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -703,7 +703,7 @@ 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)
@@ -959,6 +959,9 @@ 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

[PATCH AUTOSEL 4.19 007/172] iio: light: isl29125: fix iio_triggered_buffer_{predisable,postenable} positions

[Sasha Levin]

From: Alexandru Ardelean <alexandru.ardelean@analog.com>

[ Upstream commit 9b7a12c3e090cf3fba6f66f1f23abbc6e0e86021 ]

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

This change reworks the predisable/postenable hooks so that the pollfunc is
attached/detached in the correct position.
It also balances the calls a bit, by grouping the preenable and the
iio_triggered_buffer_postenable() into a single
isl29125_buffer_postenable() function.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/light/isl29125.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/light/isl29125.c b/drivers/iio/light/isl29125.c
index ed38edcd5efe..2175cb9c2908 100644
--- a/drivers/iio/light/isl29125.c
+++ b/drivers/iio/light/isl29125.c
@@ -216,13 +216,24 @@ static const struct iio_info isl29125_info = {
 	.attrs = &isl29125_attribute_group,
 };
 
-static int isl29125_buffer_preenable(struct iio_dev *indio_dev)
+static int isl29125_buffer_postenable(struct iio_dev *indio_dev)
 {
 	struct isl29125_data *data = iio_priv(indio_dev);
+	int err;
+
+	err = iio_triggered_buffer_postenable(indio_dev);
+	if (err)
+		return err;
 
 	data->conf1 |= ISL29125_MODE_RGB;
-	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+	err = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
 		data->conf1);
+	if (err) {
+		iio_triggered_buffer_predisable(indio_dev);
+		return err;
+	}
+
+	return 0;
 }
 
 static int isl29125_buffer_predisable(struct iio_dev *indio_dev)
@@ -230,19 +241,18 @@ static int isl29125_buffer_predisable(struct iio_dev *indio_dev)
 	struct isl29125_data *data = iio_priv(indio_dev);
 	int ret;
 
-	ret = iio_triggered_buffer_predisable(indio_dev);
-	if (ret < 0)
-		return ret;
-
 	data->conf1 &= ~ISL29125_MODE_MASK;
 	data->conf1 |= ISL29125_MODE_PD;
-	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+	ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
 		data->conf1);
+
+	iio_triggered_buffer_predisable(indio_dev);
+
+	return ret;
 }
 
 static const struct iio_buffer_setup_ops isl29125_buffer_setup_ops = {
-	.preenable = isl29125_buffer_preenable,
-	.postenable = &iio_triggered_buffer_postenable,
+	.postenable = isl29125_buffer_postenable,
 	.predisable = isl29125_buffer_predisable,
 };
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 019/172] iio: bmp280: fix compensation of humidity

[Sasha Levin]

From: Andreas Klinger <ak@it-klinger.de>

[ Upstream commit dee2dabc0e4115b80945fe2c91603e634f4b4686 ]

Limit the output of humidity compensation to the range between 0 and 100
percent.

Depending on the calibration parameters of the individual sensor it
happens, that a humidity above 100 percent or below 0 percent is
calculated, which don't make sense in terms of relative humidity.

Add a clamp to the compensation formula as described in the datasheet of
the sensor in chapter 4.2.3.

Although this clamp is documented, it was never in the driver of the
kernel.

It depends on the circumstances (calibration parameters, temperature,
humidity) if one can see a value above 100 percent without the clamp.
The writer of this patch was working with this type of sensor without
noting this error. So it seems to be a rare event when this bug occures.

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/pressure/bmp280-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index d47922a1d0f3..074f6f865008 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -261,6 +261,8 @@ static u32 bmp280_compensate_humidity(struct bmp280_data *data,
 		+ (s32)2097152) * calib->H2 + 8192) >> 14);
 	var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)calib->H1) >> 4;
 
+	var = clamp_val(var, 0, 419430400);
+
 	return var >> 12;
 };
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 059/172] iio: buffer: Don't allow buffers without any channels enabled to be activated

[Sasha Levin]

From: Lars-Peter Clausen <lars@metafoo.de>

[ Upstream commit b7329249ea5b08b2a1c2c3f24a2f4c495c4f14b8 ]

Before activating a buffer make sure that at least one channel is enabled.
Activating a buffer with 0 channels enabled doesn't make too much sense and
disallowing this case makes sure that individual driver don't have to add
special case code to handle it.

Currently, without this patch enabling a buffer is possible and no error is
produced. With this patch -EINVAL is returned.

An example of execution with this patch and some instrumented print-code:
   root@analog:~# cd /sys/bus/iio/devices/iio\:device3/buffer
   root@analog:/sys/bus/iio/devices/iio:device3/buffer# echo 1 > enable
   0: iio_verify_update 748 indio_dev->masklength 2 *insert_buffer->scan_mask 00000000
   1: iio_verify_update 753
   2:__iio_update_buffers 1115 ret -22
   3: iio_buffer_store_enable 1241 ret -22
   -bash: echo: write error: Invalid argument
1, 2 & 3 are exit-error paths. 0 the first print in iio_verify_update()
rergardless of error path.

Without this patch (and same instrumented print-code):
   root@analog:~# cd /sys/bus/iio/devices/iio\:device3/buffer
   root@analog:/sys/bus/iio/devices/iio:device3/buffer# echo 1 > enable
   0: iio_verify_update 748 indio_dev->masklength 2 *insert_buffer->scan_mask 00000000
   root@analog:/sys/bus/iio/devices/iio:device3/buffer#
Buffer is enabled with no error.

Note from Jonathan: Probably not suitable for automatic application to stable.
This has been there from the very start.  It tidies up an odd corner
case but won't effect any 'real' users.

Fixes: 84b36ce5f79c0 ("staging:iio: Add support for multiple buffers")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/industrialio-buffer.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index a0d089afa1a2..b1e9ac5ecdac 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -691,6 +691,13 @@ static int iio_verify_update(struct iio_dev *indio_dev,
 	bool scan_timestamp;
 	unsigned int modes;
 
+	if (insert_buffer &&
+	    bitmap_empty(insert_buffer->scan_mask, indio_dev->masklength)) {
+		dev_dbg(&indio_dev->dev,
+			"At least one scan element must be enabled first\n");
+		return -EINVAL;
+	}
+
 	memset(config, 0, sizeof(*config));
 	config->watermark = ~0;
 
-- 
2.25.1