Commit Graph

4 Commits

Author SHA1 Message Date
Laurent Pinchart
dd8b6a2cc9 cam: drm: Avoid importing the same dmabuf multiple times
When creating a DRM frame buffer, the dmabufs for the planes are
imported as GEM objects. For multi-planar formats, all planes may use
the same dmabuf, which results in multiple imports. This doesn't cause
any issue at import time, as DRM detects this situation and returns the
same GEM object. However, when destroying the frame buffer, the same GEM
object ends up being closed multiple times, which generates an error.

Fix this by avoiding multiple imports of the same dmabuf for the same
frame buffer. While the issue may theoretically occur with identical
dmabufs for different frame buffers, this is quite unlikely and is thus
not addressed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-09-07 19:18:48 +03:00
Laurent Pinchart
71dad75373 cam: drm: Set per-plane offsets when creating DRM frame buffer
Now that libcamera supports per-plane offsets, pass the values to
drmModeAddFB2(). The KMS sink in cam is now capable of rendering
multi-planar formats.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-09-07 19:18:47 +03:00
Laurent Pinchart
843048499f cam: drm: Support per-plane stride values
The stride is not always identical for all planes for multi-planar
formats. Semi-planar YUV formats without horizontal subsampling often
have a chroma stride equal to twice the luma stride, and tri-planar YUV
formats with a 1/2 horizontal subsampling often have a chroma stride
equal to half the luma stride. This isn't correctly taken into account
when creating a DRM frame buffer, as the same stride is set for all
planes.

libcamera doesn't report per-plane stride values yet, but uses chroma
strides that match the above description for all currently supported
platforms. Calculation the chrome strides appropriately in the KMSSink
class, and pass them to DRM::createFrameBuffer().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-09-07 19:18:45 +03:00
Laurent Pinchart
910b5253cb cam: Add DRM helper classes
To prepare for viewfinder operation through the DRM/KMS API, add a set
of helper classes that encapsulate the libdrm functions.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-08-05 16:23:11 +03:00