[1/5] pipeline_handler: Fix unlocking media devices too early when there are multiple cameras
diff mbox series

Message ID 20240820195016.16028-2-hdegoede@redhat.com
State New
Headers show
Series
  • Fix uvcvideo pipelinehandler keeping /dev/video# open
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Commit Message

Hans de Goede Aug. 20, 2024, 7:50 p.m. UTC
PipelineHandler::acquire() only locks the media devices when the first
camera is acquired. If a second camera of a pipeline is acquired only
useCount_ is increased and nothing else is done.

When releasing cameras PipelineHandler::release() should only unlock
the media devices when the last camera is released. But the old code
unlocked on every release().

Fix PipelineHandler::release() to only release the media devices when
the last camera is released.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 src/libcamera/pipeline_handler.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Hans de Goede Aug. 21, 2024, 9:57 a.m. UTC | #1
Hi,

On 8/20/24 9:50 PM, Hans de Goede wrote:
> PipelineHandler::acquire() only locks the media devices when the first
> camera is acquired. If a second camera of a pipeline is acquired only
> useCount_ is increased and nothing else is done.
> 
> When releasing cameras PipelineHandler::release() should only unlock
> the media devices when the last camera is released. But the old code
> unlocked on every release().
> 
> Fix PipelineHandler::release() to only release the media devices when
> the last camera is released.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Note this is a resend of the standalone fix which I send out earlier
since the rest of the series depends on this.

The standalone posting already has a:

Reviewed-by: Harvey Yang <chenghaoyang@chromium.org>

which I forgot to add here.

Regards,

Hans


> ---
>  src/libcamera/pipeline_handler.cpp | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> index 5a6de685..a20cd27d 100644
> --- a/src/libcamera/pipeline_handler.cpp
> +++ b/src/libcamera/pipeline_handler.cpp
> @@ -205,7 +205,8 @@ void PipelineHandler::release(Camera *camera)
>  
>  	ASSERT(useCount_);
>  
> -	unlockMediaDevices();
> +	if (useCount_ == 1)
> +		unlockMediaDevices();
>  
>  	releaseDevice(camera);
>

Patch
diff mbox series

diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 5a6de685..a20cd27d 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -205,7 +205,8 @@  void PipelineHandler::release(Camera *camera)
 
 	ASSERT(useCount_);
 
-	unlockMediaDevices();
+	if (useCount_ == 1)
+		unlockMediaDevices();
 
 	releaseDevice(camera);