diff mbox series

iio: accel: bma400: Ensure VDDIO is enable defore reading the chip ID.

Message ID 20221002144133.3771029-1-jic23@kernel.org (mailing list archive)
State Accepted
Headers show
Series iio: accel: bma400: Ensure VDDIO is enable defore reading the chip ID. | expand

Commit Message

Jonathan Cameron Oct. 2, 2022, 2:41 p.m. UTC 
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The regulator enables were after the check on the chip variant, which was
very unlikely to return a correct value when not powered.
Presumably all the device anyone is testing on have a regulator that
is already powered up when this code runs for reasons beyond the scope
of this driver. Move the read call down a few lines.

Fixes: 3cf7ded15e40 ("iio: accel: bma400: basic regulator support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Dan Robertson <dan@dlrobertson.com>
---
 drivers/iio/accel/bma400_core.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

Comments

Dan Robertson Oct. 28, 2022, 1:07 p.m. UTC | #1 
On Sun, Oct 02, 2022 at 03:41:33PM +0100, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> The regulator enables were after the check on the chip variant, which was
> very unlikely to return a correct value when not powered.
> Presumably all the device anyone is testing on have a regulator that
> is already powered up when this code runs for reasons beyond the scope
> of this driver. Move the read call down a few lines.
> 
> Fixes: 3cf7ded15e40 ("iio: accel: bma400: basic regulator support")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Reviewed-by: Dan Robertson <dan@dlrobertson.com>

Thanks for catching this!

Cheers,

 - Dan
Jonathan Cameron Oct. 29, 2022, 11:25 a.m. UTC | #2 
On Fri, 28 Oct 2022 13:07:47 +0000
Dan Robertson <dan@dlrobertson.com> wrote:

> On Sun, Oct 02, 2022 at 03:41:33PM +0100, Jonathan Cameron wrote:
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > 
> > The regulator enables were after the check on the chip variant, which was
> > very unlikely to return a correct value when not powered.
> > Presumably all the device anyone is testing on have a regulator that
> > is already powered up when this code runs for reasons beyond the scope
> > of this driver. Move the read call down a few lines.
> > 
> > Fixes: 3cf7ded15e40 ("iio: accel: bma400: basic regulator support")
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>  
> 
> Reviewed-by: Dan Robertson <dan@dlrobertson.com>
> 
> Thanks for catching this!

Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan

> 
> Cheers,
> 
>  - Dan
diff mbox series

Patch

diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
index e8de88e6cfb9..81bfec9e20cc 100644
--- a/drivers/iio/accel/bma400_core.c
+++ b/drivers/iio/accel/bma400_core.c
@@ -869,18 +869,6 @@  static int bma400_init(struct bma400_data *data)
 	unsigned int val;
 	int ret;
 
-	/* Try to read chip_id register. It must return 0x90. */
-	ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
-	if (ret) {
-		dev_err(data->dev, "Failed to read chip id register\n");
-		return ret;
-	}
-
-	if (val != BMA400_ID_REG_VAL) {
-		dev_err(data->dev, "Chip ID mismatch\n");
-		return -ENODEV;
-	}
-
 	data->regulators[BMA400_VDD_REGULATOR].supply = "vdd";
 	data->regulators[BMA400_VDDIO_REGULATOR].supply = "vddio";
 	ret = devm_regulator_bulk_get(data->dev,
@@ -902,6 +890,18 @@  static int bma400_init(struct bma400_data *data)
 	if (ret)
 		return ret;
 
+	/* Try to read chip_id register. It must return 0x90. */
+	ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
+	if (ret) {
+		dev_err(data->dev, "Failed to read chip id register\n");
+		return ret;
+	}
+
+	if (val != BMA400_ID_REG_VAL) {
+		dev_err(data->dev, "Chip ID mismatch\n");
+		return -ENODEV;
+	}
+
 	ret = bma400_get_power_mode(data);
 	if (ret) {
 		dev_err(data->dev, "Failed to get the initial power-mode\n");