Re: [PATCH v2 7/9] [media] v4l2: introduce v4l2_timeval

From: Hans Verkuil
Date: Fri Sep 18 2015 - 06:23:38 EST


On 09/18/15 12:08, Arnd Bergmann wrote:
> On Friday 18 September 2015 11:52:28 Hans Verkuil wrote:
>> On 09/18/15 11:43, Arnd Bergmann wrote:
>>> On Friday 18 September 2015 11:27:40 Hans Verkuil wrote:
>>>> Ah, OK. Got it.
>>>>
>>>> I think this is dependent on the upcoming media workshop next month. If we
>>>> decide to redesign v4l2_buffer anyway, then we can avoid timeval completely.
>>>> And the only place where we would need to convert it in the compat code
>>>> hidden in the v4l2 core (likely v4l2-ioctl.c).
>>>
>>> Ah, I think I understood the idea now, I missed that earlier when you mention
>>> the idea.
>>>
>>> So what you are saying here is that you could come up with a new unambiguous
>>> (using only __u32 and __u64 types and no pointers) format that gets exposed
>>> to a new set of ioctls, and then change the handling of the existing three
>>> formats (native 64-bit, traditional 32-bit, and 32-bit with 64-bit time_t)
>>> so they get converted into the new format by the common ioctl handling code?
>>
>> Right. Drivers only see the new struct, and only v4l2-ioctl.c (and possible
>> v4l2-compat-ioctl32.c) see the old ones.
>>
>> BTW, I will probably pick up patches 4 and 6 for 4.4. That should help a bit.
>
> Ok, thanks!
>
> I guess it's up to Mauro to pick up the first three patches?

Yes.

> As I don't see anything more to do for me here until you've had the
> discussion about the new format, I'll move on to another subsystem now.
> I have around 70 patches waiting to be submitted, plus the system call
> series.

Agreed.

Thanks again for working on this!

Regards,

Hans
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