Re: [PATCH 2/5] input: twl6040-vibra: add handler to unregister input if module is removed

From: H. Nikolaus Schaller
Date: Tue Apr 19 2016 - 03:33:23 EST



> Am 18.04.2016 um 23:12 schrieb Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>:
>
> On Mon, Apr 18, 2016 at 09:55:38PM +0200, H. Nikolaus Schaller wrote:
>> commit 1f9e1470ab34 ("Input: twl6040-vibra - use devm functions")
>>
>> converted everything to devm but we still need to call
>> input_unregister_device(info->input_dev)
>
> No, this is not needed, because devm-managed input devices will be
> unregistered automatically.

Well, it would, if the current driver would use devm for registration. But it appears not to do it that way (line 375):

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/input/misc/twl6040-vibra.c?id=refs/tags/v4.6-rc4#n375

So we either have to fix line 375 or add the proposed explicit unregister call.

Research shows me that you did propose devm_input_register_device() some years ago but this API was never included:

https://lkml.org/lkml/2012/10/29/855

>
>>
>> Solution: add back twl6040_vibra_remove to call input_unregister_device
>>
>> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
>> ---
>> drivers/input/misc/twl6040-vibra.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/input/misc/twl6040-vibra.c b/drivers/input/misc/twl6040-vibra.c
>> index 7221a00..1e9902d 100644
>> --- a/drivers/input/misc/twl6040-vibra.c
>> +++ b/drivers/input/misc/twl6040-vibra.c
>> @@ -384,8 +384,18 @@ static int twl6040_vibra_probe(struct platform_device *pdev)
>> return 0;
>> }
>>
>> +static int twl6040_vibra_remove(struct platform_device *pdev)
>> +{
>> + struct vibra_info *info = platform_get_drvdata(pdev);
>> +
>> + input_unregister_device(info->input_dev);
>> +
>> + return 0;
>> + }
>> +
>> static struct platform_driver twl6040_vibra_driver = {
>> .probe = twl6040_vibra_probe,
>> + .remove = twl6040_vibra_remove,
>> .driver = {
>> .name = "twl6040-vibra",
>> .pm = &twl6040_vibra_pm_ops,
>> --
>> 2.7.3
>>
>
> Thanks.
>
> --
> Dmitry