[libcamera-devel] [PATCH 2/2] libcamera: camera: Unmap buffers before release

[Kieran Bingham]

Hi Laurent,

On 05/03/2019 12:54, Laurent Pinchart wrote:
> Hi Kieran,
> 
> Thank you for the patch.
> 
> On Mon, Mar 04, 2019 at 11:25:30PM +0000, Kieran Bingham wrote:
>> Before buffers can be released back to V4L2 all mappings must be unmapped.
> 
> I don't think "released back to v4L2" is the right terminology. Maybe
> "Before buffers can be freed by the V4L2 device that has allocated them,
> all mappings must be destroyed" ? Same for the comment below. Apart from
> that,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Agreed, I'll reword as suggested and push with 1/2.

--
Kieran


> 
>> Ensure that buffers are released correctly by destroying the buffer pool
>> contents before freeing the resources on the stream.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>> ---
>>  src/libcamera/camera.cpp | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
>> index 8e17085bfb50..875e1e46c89c 100644
>> --- a/src/libcamera/camera.cpp
>> +++ b/src/libcamera/camera.cpp
>> @@ -488,8 +488,13 @@ int Camera::freeBuffers()
>>  		if (!stream->bufferPool().count())
>>  			continue;
>>  
>> -		pipe_->freeBuffers(this, stream);
>> +		/*
>> +		 * Destroy Buffers will empty the pool, and unmap any existing
>> +		 * memory mapping. This needs to be done before releasing
>> +		 * buffers back to the V4L2Device through freeBuffers().
>> +		 */
>>  		stream->bufferPool().destroyBuffers();
>> +		pipe_->freeBuffers(this, stream);
>>  	}
>>  
>>  	state_ = CameraConfigured;
> 

-- 
Regards
--
Kieran