New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[WIP] alternative split devices #417

Closed

umlaeute wants to merge 28 commits into develop from feature/split-device

Owner

umlaeute commented Mar 18, 2021

this is just an alternative branch to #359

it's main purpose is to keep the possibility for joined devices, pulling in the changes from #359 every now and then.

this PR is not very actively pursued. it's only a PR to get GitHub-actions (without changing the workflows-configuration)

vicamo and others added 24 commits

March 13, 2021 19:55


          clang-format

1a9445e

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          Merge remote-tracking branch 'vicamo-github/for-upstream/fix-v4l2-com…

d3f7442

…pliance-errors'


          drop hacks for linux<<3

1ca5cce


          mention that linux<<3.0.0 is unsupported

7bace70


          drop VIDIOCGMBUF support

89b476b

V4L1 has been completely removed from kernel since 2.6.39.


          drop useless address-operator from function-tables

790a046


          mod: add output_nr module parameter in parallel with video_nr

c256fb7

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          keep track of both output_nr and capture_nr in IDR

03366a7

With this change, output_nr will be allocated and deallocated as
capture_nr is, but currently saved with no other reference to it.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          refactor v4l2loopback_lookup

727e625

Since now both output_nr and capture_nr are meaningful, don't return
either of them.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          cache vdev for latter uses

32cbef3

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          embed struct video_device into v4l2_loopback_device

6c6a6c1

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          set v4l2_loopback_device addr as video_device drvdata instead

c580737

Converting function v4l2loopback_cd2dev and v4l2loopback_getdevice
searches v4l2loopback_index_idr with device number retrieved from
video_device drvdata, but this could be time consuming and creates
unecessary complexity. And since we may need to retrieve
v4l2_loopback_device address from callbacks shared between capture and
output devices, this patch reuses video_device drvdata instead of struct
member offsets.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          move v4l2_loopback_device->vdev into v4l2_loopback_device->capture

fd056bd

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          move all vdev init procedures into init_vdev

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          fix cap->device_caps may not be defined before v3.3

68616dd

Also use V4L2_CAP_DEVICE_CAPS to detect this instead of hardcoded kernel
version.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          don't change device state in vidioc_s_fmt_out

eeb0625

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          create a draft output video_device

50e2fcf

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          remove dev->output_nr

210e307

Since we have already instantiated an output video device, use its `num`
field instead.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          output: add ioctl handlers

babaffe

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          re-implement a separate output device

2f0fb5a

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          prepare to share output/capture entity init

4e0ef85

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          capture: init vb2_queue

6d4a482

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          capture: use fops callback from videobuf2

37c700e

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>


          [wip] reimplement capture entity using videobuf2

ac6439b

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>

umlaeute changed the base branch from main to develop

March 18, 2021 09:39


          Merge branch 'develop' into split-device

8a94f49

Contributor

vicamo commented Mar 19, 2021

Hi, I'd like to point out that struct vb2_queue has a streaming member, and vb2_core_streamon called in vb2_streamon called in vb2_ioctl_streamon would check if it's already in streaming, so it's impossible to share a struct vb2_queue between capture/output because VIDIOC_STREAMON cannot be called twice. So if you'd like to use videobuf2 queue/buf management with joined devices, you'll cannot use these ioctl helper functions, and you cannot use videobuf2 provided fops helper functions directly, either. They check vdev->queue for most calls. You'll need various work-arounds for very detailed implementation level limitations. It's going to be a mess.

umlaeute added 3 commits

March 19, 2021 10:57


          clang-format


          simplified capabilities logic (with only split-devices), setting CAPT…

3a1ab9a

…URE only for capture devices


          set device transfer direction

2e76bec

umlaeute force-pushed the feature/split-device branch from 89d86fc to 2e76bec Compare

March 19, 2021 09:59

Owner Author

umlaeute commented Mar 19, 2021

i think #268 (comment) made it clear that joint devices is not sustainable anyhow.

I'm therefore closing this wip-pr.

the feature/split-devices branch has been rebooted by force-push to be based on your PR #359. (please sync to that as well :-))

(for reference sake, there's another branch that keeps the original content of this PR)

umlaeute closed this

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet