Teathered capture with Canon R6 MK II locks camera controls

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

Opening a tethered capture session locks the camera controls limiting the usefulness of this feature. I dug around a bit and figured it was likely a problem with libgphoto2 and found an issue that seems to be the cause.

This issue for gphoto2 seems to indicate an additional flag on the start of the session may be needed for this model and a couple others. Setting disablemodedial to 0 looks like an option to try.

Steps to reproduce

1. Connect camera via USB-C camera
2. Open a teather capture
3. Live view and controls work as expected on darktable but the local camera controls remain locked

Expected behavior

Open a session without locking the local camera controls

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.4.1

What OS are you using?

Linux

What is the version of your OS?

Arch rolling

Describe your system

No response

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

AMD Radeon via OpenCL with ROCM

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

Start by reproducing the tethered-capture session with a Canon R6 Mark II on Linux and review libgphoto2 issue 1210, especially the suggested disablemodedial setting. Trace the tethered-capture startup path in darktable to determine how the camera session is opened. Done means the session opens without locking the camera's local controls.