[PATCH] iio: accel: hid-sensor-accel-3d: Fix duplicate scan index error

[PATCH] iio: accel: hid-sensor-accel-3d: Fix duplicate scan index error

[Srinivas Pandruvada]

When both accel_3d and gravity sensor are present, iio_device_register()
fails with "Duplicate scan index" error.
The reason for this is setting of indio_dev->num_channels based on
accel_3d channel for both gravity and accel-3d sensor. But number of
channels are not same, so for gravity it is pointing to some invalid
memory and getting scan_index to compare which may match.
To fix this issue, set the indio_dev->num_channels correctly based on
the sensor type.

Fixes: 0e377f3b9ae9 ('iio: Add gravity sensor support')
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/accel/hid-sensor-accel-3d.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/accel/hid-sensor-accel-3d.c b/drivers/iio/accel/hid-sensor-accel-3d.c
index ca5759c..43a6cb0 100644
--- a/drivers/iio/accel/hid-sensor-accel-3d.c
+++ b/drivers/iio/accel/hid-sensor-accel-3d.c
@@ -370,10 +370,12 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
 		name = "accel_3d";
 		channel_spec = accel_3d_channels;
 		channel_size = sizeof(accel_3d_channels);
+		indio_dev->num_channels = ARRAY_SIZE(accel_3d_channels);
 	} else {
 		name = "gravity";
 		channel_spec = gravity_channels;
 		channel_size = sizeof(gravity_channels);
+		indio_dev->num_channels = ARRAY_SIZE(gravity_channels);
 	}
 	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
 					&accel_state->common_attributes);
@@ -395,7 +397,6 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
 		goto error_free_dev_mem;
 	}
 
-	indio_dev->num_channels = ARRAY_SIZE(accel_3d_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &accel_3d_info;
 	indio_dev->name = name;
-- 
2.7.4

Re: [PATCH] iio: accel: hid-sensor-accel-3d: Fix duplicate scan index error

[Jonathan Cameron]

On 30/03/17 00:23, Srinivas Pandruvada wrote:
> When both accel_3d and gravity sensor are present, iio_device_register()
> fails with "Duplicate scan index" error.
> The reason for this is setting of indio_dev->num_channels based on
> accel_3d channel for both gravity and accel-3d sensor. But number of
> channels are not same, so for gravity it is pointing to some invalid
> memory and getting scan_index to compare which may match.
> To fix this issue, set the indio_dev->num_channels correctly based on
> the sensor type.
> 
> Fixes: 0e377f3b9ae9 ('iio: Add gravity sensor support')
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Applied to fixes-togreg branch of iio.git.

Thanks,

Jonathan
> ---
>  drivers/iio/accel/hid-sensor-accel-3d.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/accel/hid-sensor-accel-3d.c b/drivers/iio/accel/hid-sensor-accel-3d.c
> index ca5759c..43a6cb0 100644
> --- a/drivers/iio/accel/hid-sensor-accel-3d.c
> +++ b/drivers/iio/accel/hid-sensor-accel-3d.c
> @@ -370,10 +370,12 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
>  		name = "accel_3d";
>  		channel_spec = accel_3d_channels;
>  		channel_size = sizeof(accel_3d_channels);
> +		indio_dev->num_channels = ARRAY_SIZE(accel_3d_channels);
>  	} else {
>  		name = "gravity";
>  		channel_spec = gravity_channels;
>  		channel_size = sizeof(gravity_channels);
> +		indio_dev->num_channels = ARRAY_SIZE(gravity_channels);
>  	}
>  	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
>  					&accel_state->common_attributes);
> @@ -395,7 +397,6 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
>  		goto error_free_dev_mem;
>  	}
>  
> -	indio_dev->num_channels = ARRAY_SIZE(accel_3d_channels);
>  	indio_dev->dev.parent = &pdev->dev;
>  	indio_dev->info = &accel_3d_info;
>  	indio_dev->name = name;
>