[libcamera-devel] [PATCH] cam: kms_sink: select valid crtc

[Eric Curtin]

When looping through possibleCrtcs on my machine, the only valid crtc is
actually the first one. This can be identified by checking if the clock
variable is non-zero.

Signed-off-by: Eric Curtin <ecurtin at redhat.com>
---
 src/cam/drm.cpp      | 2 +-
 src/cam/drm.h        | 2 ++
 src/cam/kms_sink.cpp | 4 ++++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/cam/drm.cpp b/src/cam/drm.cpp
index f2530091..808e5a87 100644
--- a/src/cam/drm.cpp
+++ b/src/cam/drm.cpp
@@ -128,7 +128,7 @@ std::unique_ptr<Blob> Mode::toBlob(Device *dev) const
 }
 
 Crtc::Crtc(Device *dev, const drmModeCrtc *crtc, unsigned int index)
-	: Object(dev, crtc->crtc_id, Object::TypeCrtc), index_(index)
+	: Object(dev, crtc->crtc_id, Object::TypeCrtc), index_(index), crtc_(crtc)
 {
 }
 
diff --git a/src/cam/drm.h b/src/cam/drm.h
index de57e445..d05e6d13 100644
--- a/src/cam/drm.h
+++ b/src/cam/drm.h
@@ -149,12 +149,14 @@ public:
 	Crtc(Device *dev, const drmModeCrtc *crtc, unsigned int index);
 
 	unsigned int index() const { return index_; }
+	uint32_t clock() const { return crtc_->mode.clock; }
 	const std::vector<const Plane *> &planes() const { return planes_; }
 
 private:
 	friend Device;
 
 	unsigned int index_;
+	const drmModeCrtc *crtc_;
 	std::vector<const Plane *> planes_;
 };
 
diff --git a/src/cam/kms_sink.cpp b/src/cam/kms_sink.cpp
index d30fba78..aa0b7a3c 100644
--- a/src/cam/kms_sink.cpp
+++ b/src/cam/kms_sink.cpp
@@ -166,6 +166,10 @@ int KMSSink::configurePipeline(const libcamera::PixelFormat &format)
 	 */
 	for (const DRM::Encoder *encoder : connector_->encoders()) {
 		for (const DRM::Crtc *crtc : encoder->possibleCrtcs()) {
+			if (!crtc->clock()) {
+				continue;
+			}
+
 			for (const DRM::Plane *plane : crtc->planes()) {
 				if (plane->type() != DRM::Plane::TypePrimary)
 					continue;
-- 
2.33.1