On 11/04/2024 14:48, Umang Jain wrote:
Hi Tomi,
On 11/04/24 4:37 pm, Tomi Valkeinen wrote:
On 11/04/2024 14:02, Umang Jain wrote:
Hi Tomi,
On 10/04/24 6:05 pm, Tomi Valkeinen wrote:
At the moment the v4l2_subdev_enable/disable_streams() functions call
fallback helpers to handle the case where the subdev only implements
.s_stream(), and the main function handles the case where the subdev
implements streams (V4L2_SUBDEV_FL_STREAMS, which implies
.enable/disable_streams()).
What is missing is support for subdevs which do not implement streams
support, but do implement .enable/disable_streams(). Example cases of
these subdevices are single-stream cameras, where using
.enable/disable_streams() is not required but helps us remove the users
of the legacy .s_stream(), and subdevices with multiple source pads
(but
single stream per pad), where .enable/disable_streams() allows the
subdevice to control the enable/disable state per pad.
The two single-streams cases (.s_stream() and
.enable/disable_streams())
are very similar, and with small changes we can change the
v4l2_subdev_enable/disable_streams() functions to support all three
cases, without needing separate fallback functions.
A few potentially problematic details, though:
Does this mean the patch needs to be worked upon more ?
I don't see the two issues below as blockers.
I quickly tested the series by applying it locally with my use case
of IMX283 .enable/disable streams and s_stream as the helper function
and it seems I am still seeing the same behaviour as before (i.e. not
being streamed) and have to carry the workaround as mentioned in [1]
**NOTE**
Ok... Then something bugs here, as it is supposed to fix the problem.
Can you trace the code a bit to see where it goes wrong?
The execution should go to the "if (!(sd->flags &
V4L2_SUBDEV_FL_STREAMS))" blocks in v4l2_subdev_collect_streams() and
v4l2_subdev_set_streams_enabled(),
The execution is not reaching in v4l2_subdev_collect streams() even, it
returns at
if (!streams_mask)
return 0;
in v4l2_subdev_enable_streams()
Refer to : https://paste.debian.net/1313760/
My tree is based on v6.8 currently, but the series applies cleanly, so I
have not introduced any rebase artifacts. If you think, v6.8 might be
causing issues, I'll then try to test on RPi 5 with the latest media
tree perhaps.
So who is calling the v4l2_subdev_enable_streams? I presume it comes
from v4l2_subdev_s_stream_helper(), in other words the sink side in your
pipeline is using legacy s_stream?
Indeed, that helper still needs work. It needs to detect if there's no
routing, and use the implicit stream 0. I missed that one.
Tomi
