Re: [QUESTION] staging/easycap fix

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Ezequiel,

The post: Intro to V4L2:
http://www.linuxfordevices.com/c/a/Linux-For-Devices-Articles/Intro-to-V4L2/

And the post: The VIVI driver; a great starting point for V4L2 driver writers:
http://lwn.net/Articles/203971/

May be useful.

[]'s

Peter


2012/2/14 Greg KH <greg@xxxxxxxxx>:
> On Tue, Feb 14, 2012 at 07:01:25PM -0300, Ezequiel García wrote:
>> Hi Greg,
>>
>> >
>> > It's only "recommended" if you have a compiler that doesn't check for
>> > such foolish things.
>> >
>>
>> Understood. Thanks both.
>>
>> Another question (hope you don't mind me asking so much):
>>
>> I noticed easycap does lots of (redundant?) checks as:
>>
>> pvideo_device = video_devdata(file);
>> if (!pvideo_device) {
>>   return -EFAULT;
>> }
>>
>> Is this bad, good or doesn't matter?
>> (There are more examples where the check is clearly not needed but
>> this one makes me doubt a bit)
>
> Depends on what video_devdata() does, and how it could ever be NULL.
>
>> Maybe I'm focusing on small issues (as you already pointed out),
>> do you think this kind of patches would be accepted?
>>
>> Of course, I would submit separate patches, one for each change:
>> 1. split probe function
>> 2. remove redundant checks
>> 3. clean comment style
>> ... and so on.
>
> That sounds great.
>
>> Also, I'm reading driver cx231xx as it's also an usb video capture.
>> Do you think it's a good code reference? Can you give me further reference?
>
> I don't know, ask the linux-media developers on their list for a good
> reference driver to follow, they would know best.
>
> thanks,
>
> greg k-h
>
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-- 
Peter Senna Tschudin
peter.senna@xxxxxxxxx
gpg id: 48274C36

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