Behavior of ENUM_STD/G_STD ioctl

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Hi,

I am working on OMAP3517 which has CCDC module which is almost similar to Davinci (DM6446). I have ported davinci capture driver (Submitted by Murali) to OMAP3517, and I am almost done with it, except some hardware related issues (which requires some follow-ups with HW team). 

During this I came across one observation, in vpfe_camera.c file which is bridge driver assumes the default standard without looking/referring to underneath sub-device (It choose index 0 in the v4l2_std array maintained by bridge driver). If I understand correctly as per V4L2 Spec, the driver does not need to implement enum_std/g_std callback functions, since V4L2 layer handles this and returns these fields respectively. 

Now the question I have here is, how enum_std/g_std, to be more specific tvnorm/current_norm should be handled by driver?

1) During probe (or open) bridge driver should get the current standard which is being active from the underneath sub-device and update the fields tvnorm/current_norm accordingly. After that whenever application call enum_std/g_std the V4L2 layer can handle it and for s_std anyway bridge driver passing it to sub device.

2) Application must call s_std and that's where all the path will get synchronized (what sub-device has with what V4L2 layer has against bridge driver)

I believe driver should follow option 1, especially in our case (TVP5146 video decoder) where it has a capability to lock the signal and return the status of detected standard.

Can anybody conform how this should be handled?

Thanks,
Vaibhav
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