On 06/09/2024 14:27, Tomi Valkeinen wrote:
Hi,
On 06/09/2024 14:14, Tomi Valkeinen wrote:
Hi Niklas,
On 06/09/2024 13:14, Niklas Söderlund wrote:
Hi Tomi,
Thanks for your report.
I have an on-going series trying to clean this all up [1]. The one
change in the v4l-async core I proposed was however rejected and I have
yet to circle back to figure out a different solution.
Could you give it a try and see if it also solves this issue?
1. [PATCH 0/6] media: rcar-vin: Make use of multiple connections in
v4l-async
https://lore.kernel.org/linux-renesas-
soc/20240129202254.1126012-1-niklas.soderlund+renesas@xxxxxxxxxxxx/
The compilation fails (broken in media: rcar-vin: Simplify remote
source type detection) with:
drivers/media/platform/renesas/rcar-vin/rcar-dma.c:767:24: error:
‘struct rvin_dev’ has no member named ‘is_csi’
If I hack past that, I don't see the warnings anymore. But if I'm not
mistaken, rvin_release() is not called at all anymore. I can also see
plenty of leaks with kmemleak. Those seem to originate from max96712,
but... I don't see max96712's remove() getting called either when I
remove the module.
Sorry, never mind that. I had the debug print in max96714... =). So
max96712 remove() gets called, but it's missing:
+ v4l2_subdev_cleanup(&priv->sd);
+ media_entity_cleanup(&priv->sd.entity);
+ v4l2_ctrl_handler_free(&priv->ctrl_handler);
But now I'm seeing rvin_release() getting called (no warnings). I'm not
sure what changed. Maybe I had some extra changes lying around. Let me
test the series a bit more...
I haven't seen the warning anymore, so I believe your series indeed
fixes the issue.
Tomi
Tomi
I'm testing on Renesas' whitehawk board, with max96712 TPG. If you
have that board, and want to try module loading & unloading, you also
need to fix the max96712 remove function:
- struct max96712_priv *priv = i2c_get_clientdata(client);
+ struct v4l2_subdev *sd = i2c_get_clientdata(client);
+ struct max96712_priv *priv = v4l2_get_subdevdata(sd);
Tomi
On 2024-09-06 12:57:50 +0300, Tomi Valkeinen wrote:
Hi Niklas,
There seems to be a race in rcar-v4l2.c, causing
WARN_ON(entity->use_count < 0) in pipeline_pm_power_one().
If my understanding is correct, the VIN v4l2 nodes are being created
(rvin_v4l2_register), meaning they are userspace accessible, but the
media
pipeline as a whole is not ready yet (e.g. media links).
So what happens is that after some video nodes have been created, the
userspace opens them (I think it's udevd checking the new device
nodes),
causing rvin_open(). rvin_open() goes through the media graph and
does some
PM enabling (I'm not familiar with the legacy v4l2_pipeline_pm_get()).
However, as the links are not there, it doesn't really enable much
at all.
Then the driver goes forward and finishes with the media graph.
Then the userspace closes the opened video nodes, rvin_release()
gets called
and it goes through the media graph, which now contains all the
entities,
and powers them down. As the entities were never powered up, we hit the
use_count warning.
This happens quite often to me when loading the modules, but I think
it can
be made to happen more often by adding msleep(1000) to the beginning of
rvin_release(), thus ensuring that the graph setup is finished
before the
rvin_release() proceeds (and hoping that the graph setup was not
ready when
rvin_open() was called).
Tomi
