On 14/09/15 17:08, Vaishali Thakkar wrote:
> Use resourced managed function devm_iio_device_register to
> make error path simpler. To be compatible with the change,
> the remove function is removed as it is now redundant.
>
> Signed-off-by: Vaishali Thakkar <vthakkar1994@xxxxxxxxx>
This patch is reasonable, but makes me wonder if there is an issue
in the remove path for this driver. It relies on the ssp_sensors common
module. That in ssp_spi.c uses the fact ssp_register_consumer
has saved the struct iio_dev into a local array in the core driver.
I think this means that a remove of this function will leave a possible
null pointer de reference.
Now I suspect that case doesn't actually occur because the relevant
device elements are disabled whenever this module is removed. Having
said that we might expect an ssp_unregister_consumer function that
sets the relevant pointer back to null on removal so as to avoid
any possible race conditions around driver removal / reprobing.
A spot of defensive programming rather than necessarily a bug to be
fixed!
One little process thing. This driver was written by Karol so patches
should probably always cc Karol as well as the more general
maintainer / reviewers for IIO. Added cc.
Jonathan
> ---
> drivers/iio/gyro/ssp_gyro_sensor.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/drivers/iio/gyro/ssp_gyro_sensor.c b/drivers/iio/gyro/ssp_gyro_sensor.c
> index 0a8afdd..ac88de7 100644
> --- a/drivers/iio/gyro/ssp_gyro_sensor.c
> +++ b/drivers/iio/gyro/ssp_gyro_sensor.c
> @@ -134,7 +134,7 @@ static int ssp_gyro_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, indio_dev);
>
> - ret = iio_device_register(indio_dev);
> + ret = devm_iio_device_register(&pdev->dev, indio_dev);
> if (ret < 0)
> return ret;
>
> @@ -144,21 +144,11 @@ static int ssp_gyro_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int ssp_gyro_remove(struct platform_device *pdev)
> -{
> - struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> -
> - iio_device_unregister(indio_dev);
> -
> - return 0;
> -}
> -
> static struct platform_driver ssp_gyro_driver = {
> .driver = {
> .name = SSP_GYROSCOPE_NAME,
> },
> .probe = ssp_gyro_probe,
> - .remove = ssp_gyro_remove,
> };
>
> module_platform_driver(ssp_gyro_driver);
>
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