On 05/16/18 11:23, Oliver Neukum wrote:
> Am Dienstag, den 15.05.2018, 18:01 +0200 schrieb Hans Verkuil:
>> On 05/15/2018 05:46 PM, Oliver Neukum wrote:
>>> Am Dienstag, den 15.05.2018, 16:28 +0200 schrieb Hans Verkuil:
>>>> On 05/15/18 15:07, Oliver Neukum wrote:
>
>>>>> usbtv_audio_fail:
>>>>> /* we must not free at this point */
>>>>> - usb_get_dev(usbtv->udev);
>>>>> + v4l2_device_get(&usbtv->v4l2_dev);
>>>>
>>>> This is very confusing. I think it is much better to move the
>>>
>>> Yes. It confused me.
>>>
>>>> v4l2_device_register() call from usbtv_video_init to this probe function.
>>>
>>> Yes, but it is called here. So you want to do it after registering the
>>> audio?
>>
>> No, before. It's a global data structure, so this can be done before the
>> call to usbtv_video_init() as part of the top-level initialization of the
>> driver.
>
> Eh, but we cannot create a V4L device before the first device
> is connected and we must certainly create multiple V4L devices if
> multiple physical devices are connected.
v4l2_device_register is a terrible name. It does not create devices
or register with anything, it just initializes a root data structure. I have
proposed renaming this to v4l2_root_init() in the past, but people didn't
want a big rename action.
BTW, with 'global data structure' I meant a data structure in struct usbtv.
All I meant to say is that v4l2_device_register should be called in probe(),
not in usbtv_video_init().
Regards,
Hans
>
> Maybe I am dense. Please elaborate.
> It seem to me that the driver is confusing because it uses
> multiple refcounts.
>
> Regards
> Oliver
>
