iio: adc: exynos-adc: Fix NULL pointer exception on unbind

Fix NULL pointer exception on device unbind when device tree does not
contain "has-touchscreen" property.  In such case the input device is
not registered so it should not be unregistered.

    $ echo "12d10000.adc" > /sys/bus/platform/drivers/exynos-adc/unbind

    Unable to handle kernel NULL pointer dereference at virtual address 00000474
    ...
    (input_unregister_device) from [<c0772060>] (exynos_adc_remove+0x20/0x80)
    (exynos_adc_remove) from [<c0587d5c>] (platform_drv_remove+0x20/0x40)
    (platform_drv_remove) from [<c05860f0>] (device_release_driver_internal+0xdc/0x1ac)
    (device_release_driver_internal) from [<c0583ecc>] (unbind_store+0x60/0xd4)
    (unbind_store) from [<c031b89c>] (kernfs_fop_write+0x100/0x1e0)
    (kernfs_fop_write) from [<c029709c>] (__vfs_write+0x2c/0x17c)
    (__vfs_write) from [<c0297374>] (vfs_write+0xa4/0x184)
    (vfs_write) from [<c0297594>] (ksys_write+0x4c/0xac)
    (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28)

Fixes: 2bb8ad9b44 ("iio: exynos-adc: add experimental touchscreen support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Krzysztof Kozlowski 2019-02-09 00:39:27 +01:00 committed by Jonathan Cameron
parent 905889b4a3
commit 2ea8bab4dd
1 changed files with 1 additions and 1 deletions

View File

@ -929,7 +929,7 @@ static int exynos_adc_remove(struct platform_device *pdev)
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct exynos_adc *info = iio_priv(indio_dev);
if (IS_REACHABLE(CONFIG_INPUT)) {
if (IS_REACHABLE(CONFIG_INPUT) && info->input) {
free_irq(info->tsirq, info);
input_unregister_device(info->input);
}