commit 2ea8bab4dd upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ffe5a99203