Make legacy librealsense compatible with recent kernel

[doisyg]

This should make it work with 4.16+ kernel
Tested with a R200, not sure about the behavior with other cams

[vmatare]

This seems much nicer than what I did in #3749. That was basically just a desperate hack because we needed it to work ASAP. I'd much rather merge this than #3749.

[marcmateumateus]

Hi,
I have been playing with the modified code, it works fine with R200 and SR300 but it does not work with the ZR300 camera... I have made some modifications to uvc-v4l2.cpp in order for this camera to work.
Modifications:
To add support for ZR300 the same condition "if(sub->is_metastream)" has to be added after the line 781, otherwise it uses one of the metastreams and throws the following error: VIDIOC_S_FMT: 22, and after the line 822 as otherwise it will not add correctly the Fish_eye camera.
Thanks!

[doisyg]

Hi,
I have been playing with the modified code, it works fine with R200 and SR300 but it does not work with the ZR300 camera... I have made some modifications to uvc-v4l2.cpp in order for this camera to work.
Modifications:
To add support for ZR300 the same condition "if(sub->is_metastream)" has to be added after the line 781, otherwise it uses one of the metastreams and throws the following error: VIDIOC_S_FMT: 22, and after the line 822 as otherwise it will not add correctly the Fish_eye camera.
Thanks!

Good to know, please PR

[doisyg]

I pushed a small changes which makes multiple R200 works on my side; and also did (I think) the modification that @marcmateumateus suggested for the ZR300 (but without testing it)

[svenevs]

Add label F200 because it definitely worked for me! I didn't need to make any changes on this branch to compile / use it on linux, kernel 4.18.16 ❤️ Thank you very much for figuring this stuff out @doisyg!

[marcmateumateus]

Hi, I can confirm that it works with ZR300, sorry for not PRing, i'm kind of new to GitHub and i do not know how...
Thanks @doisyg for the changes.

Add label ZR300 and SR300 as i tested both of them.

[doisyg]

Add label ZR300 and SR300 as i tested both of them.

Good to know!

[doisyg]

@dorodnic What do you think about merging / realeasing a new version of the legacy driver? Even better releasing a new deb / ros package for librealsense

[svenevs]

It would probably make sense to remove the #include <iostream> and std::cout now?

[dorodnic]

@doisyg - I’m for it. Got some r200s to test home with but didn’t have time yet.
Not sure regarding debians, but will take a look
(We can update the rosdeb branch, but from there I’m not sure what was the flow and if it is still working)

_{Sent with GitHawk}

[doisyg]

I am sure @SteveMacenski will be happy to see this merged and released too.

[dorodnic]

Tested on 5.0.0.17 with R200, LR200 and the SR300, all working perfectly fine with the patch.
@doisyg please consider removing cout since its quite intrusive for any user app.
Also, I still need to check the ZR300 issue...

[doisyg]

@doisyg please consider removing cout since its quite intrusive for any user app.

Done

Also, I still need to check the ZR300 issue...

I think @marcmateumateus confirmed that the issue is now solved:

Hi, I can confirm that it works with ZR300

[dorodnic]

Thank you!