Hi,
On 19/06/2022 02:16, Laurent Pinchart wrote:
Hi Marek,
CC'ing Tomi to get his opinion.
On Sun, Jun 19, 2022 at 12:24:42AM +0200, Marek Vasut wrote:
Any local subdev state should be allocated and free'd using
__v4l2_subdev_state_alloc()/__v4l2_subdev_state_free(), which
takes care of calling .init_cfg() subdev op. Without this,
subdev internal state might be uninitialized by the time
any other subdev op is called.
Does this fix a bug you have? Wasn't this broken even before the active
state, as init_cfg was not called?
In any case, I think we have to do something like this, as the source
subdev might depend on a valid subdev state.
It's not very nice to have the drivers using __v4l2_subdev_state_alloc,
though. But if non-MC drivers are not going away, and if they are going
to be calling ops in other subdevs with V4L2_SUBDEV_FORMAT_TRY, they
need to pass a valid subdev state...
I don't see a better way right away, so I think this is fine.
Do we need a v4l2_subdev_call_state_try(), similar to
v4l2_subdev_call_state_active()? It would handle allocating the state,
calling the op and freeing the state.
Tomi
