[PATCH v2 1/5] iio: pressure: bmp280: Tolerate IRQ before registering

[PATCH v2 1/5] iio: pressure: bmp280: Tolerate IRQ before registering

[Andy Shevchenko]

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>
---
v2: put conditional logic back when re-initializing completion (Jonathan)
 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

[PATCH v2 2/5] iio: pressure: bmp280: Convert to use ->read_avail()

[Andy Shevchenko]

Convert to use ->read_avail() instead of open-coded attribute handling.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: new patch, which replaces previous attribute macro conversion
 drivers/iio/pressure/bmp280-core.c | 69 +++++++++++-------------------
 1 file changed, 25 insertions(+), 44 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 2540e7c2358c..ce0c1962d9f8 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -575,57 +575,38 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
-static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
+static int bmp280_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long mask)
 {
-	size_t len = 0;
-	int i;
-
-	for (i = 0; i < n; i++)
-		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
-
-	buf[len - 1] = '\n';
-
-	return len;
-}
-
-static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
-
-	return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
-				 data->chip_info->num_oversampling_temp_avail);
-}
-
-static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
+	struct bmp280_data *data = iio_priv(indio_dev);
 
-	return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
-				 data->chip_info->num_oversampling_press_avail);
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_PRESSURE:
+			*vals = data->chip_info->oversampling_press_avail;
+			*length = data->chip_info->num_oversampling_press_avail;
+			break;
+		case IIO_TEMP:
+			*vals = data->chip_info->oversampling_temp_avail;
+			*length = data->chip_info->num_oversampling_temp_avail;
+			break;
+		default:
+			return -EINVAL;
+		}
+		*type = IIO_VAL_INT;
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
 }
 
-static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
-	S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
-
-static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
-	S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
-
-static struct attribute *bmp280_attributes[] = {
-	&iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
-	&iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
-	NULL,
-};
-
-static const struct attribute_group bmp280_attrs_group = {
-	.attrs = bmp280_attributes,
-};
-
 static const struct iio_info bmp280_info = {
 	.read_raw = &bmp280_read_raw,
+	.read_avail = &bmp280_read_avail,
 	.write_raw = &bmp280_write_raw,
-	.attrs = &bmp280_attrs_group,
 };
 
 static int bmp280_chip_config(struct bmp280_data *data)
-- 
2.25.1

[PATCH v2 3/5] iio: pressure: bmp280: Explicitly mark GPIO optional

[Andy Shevchenko]

Show by using a corresponding API call that GPIO is optional.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: no change
 drivers/iio/pressure/bmp280-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index ce0c1962d9f8..263a74666c1e 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -1066,9 +1066,9 @@ int bmp280_common_probe(struct device *dev,
 	usleep_range(data->start_up_time, data->start_up_time + 100);
 
 	/* Bring chip out of reset if there is an assigned GPIO line */
-	gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	/* Deassert the signal */
-	if (!IS_ERR(gpiod)) {
+	if (gpiod) {
 		dev_info(dev, "release reset\n");
 		gpiod_set_value(gpiod, 0);
 	}
-- 
2.25.1

[PATCH v2 4/5] iio: pressure: bmp280: Drop unneeded explicit castings

[Andy Shevchenko]

In few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: no change
 drivers/iio/pressure/bmp280-core.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 263a74666c1e..958d432d9c8f 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -337,8 +337,7 @@ static int bmp280_read_temp(struct bmp280_data *data,
 	__be32 tmp = 0;
 	s32 adc_temp, comp_temp;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
-			       (u8 *) &tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
@@ -377,8 +376,7 @@ static int bmp280_read_press(struct bmp280_data *data,
 	if (ret < 0)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
-			       (u8 *) &tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
@@ -400,8 +398,8 @@ static int bmp280_read_press(struct bmp280_data *data,
 
 static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
 {
+	__be16 tmp;
 	int ret;
-	__be16 tmp = 0;
 	s32 adc_humidity;
 	u32 comp_humidity;
 
@@ -410,8 +408,7 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
 	if (ret < 0)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB,
-			       (u8 *) &tmp, 2);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp, 2);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read humidity\n");
 		return ret;
@@ -733,14 +730,14 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 
 static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
 {
+	__be16 tmp;
 	int ret;
-	__be16 tmp = 0;
 
 	ret = bmp180_measure(data, BMP180_MEAS_TEMP);
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2);
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2);
 	if (ret)
 		return ret;
 
@@ -837,7 +834,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH v2 5/5] iio: pressure: bmp280: Join string literals back

[Andy Shevchenko]

For easy grepping on debug purposes join string literals back in
the messages.

No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: no change
 drivers/iio/pressure/bmp280-core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 958d432d9c8f..a33048390118 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -943,8 +943,7 @@ static int bmp085_fetch_eoc_irq(struct device *dev,
 
 	irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
 	if (irq_trig != IRQF_TRIGGER_RISING) {
-		dev_err(dev, "non-rising trigger given for EOC interrupt, "
-			"trying to enforce it\n");
+		dev_err(dev, "non-rising trigger given for EOC interrupt, trying to enforce it\n");
 		irq_trig = IRQF_TRIGGER_RISING;
 	}
 
-- 
2.25.1

Re: [PATCH v2 1/5] iio: pressure: bmp280: Tolerate IRQ before registering

[Linus Walleij]

On Mon, Mar 23, 2020 at 11:41 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> 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>
> ---
> v2: put conditional logic back when re-initializing completion (Jonathan)

Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v2 1/5] iio: pressure: bmp280: Tolerate IRQ before registering

[Jonathan Cameron]

On Fri, 27 Mar 2020 11:50:25 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

> On Mon, Mar 23, 2020 at 11:41 AM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> 
> > 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>
> > ---
> > v2: put conditional logic back when re-initializing completion (Jonathan)  
> 
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to poke at them.

Thanks,

Jonathan

> 
> Yours,
> Linus Walleij