[v2] libcamera: software_isp: Probe EGL availability before creating DebayerEGL
diff mbox series

Message ID 20260610093812.3604734-1-qi.hou@nxp.com
State New
Headers show
Series
  • [v2] libcamera: software_isp: Probe EGL availability before creating DebayerEGL
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Commit Message

Qi Hou June 10, 2026, 9:38 a.m. UTC 
When HAVE_DEBAYER_EGL is enabled, the SoftwareIsp constructor
unconditionally creates a DebayerEGL instance. If the platform lacks
EGL surfaceless support, DebayerEGL::start() fails with -ENODEV after
SwStatsCpu ownership has already been moved, making fallback to
DebayerCpu impossible.

Add a static eGL::isAvailable() method that probes whether EGL
surfaceless rendering can be initialised. Extract the common display
obtaining logic (eglBindAPI, eglGetPlatformDisplay, eglInitialize)
into a private eGL::probeDisplay() helper that is shared by both
isAvailable() and initEGLContext(), avoiding code duplication.

The SoftwareIsp constructor now calls eGL::isAvailable() before
creating DebayerEGL. If EGL is not available, the existing fallback
path creates a DebayerCpu instance instead.

Signed-off-by: Qi Hou <qi.hou@nxp.com>
---
 include/libcamera/internal/egl.h            |  4 ++
 src/libcamera/egl.cpp                       | 60 ++++++++++++++++-----
 src/libcamera/software_isp/software_isp.cpp | 10 +++-
 3 files changed, 58 insertions(+), 16 deletions(-)

Patch
diff mbox series 

diff --git a/include/libcamera/internal/egl.h b/include/libcamera/internal/egl.h
index 57f90d93..27c5c29d 100644
--- a/include/libcamera/internal/egl.h
+++ b/include/libcamera/internal/egl.h
@@ -99,6 +99,8 @@  private:
 class eGL
 {
 public:
+	static bool isAvailable();
+
 	eGL();
 	~eGL();
 
@@ -127,6 +129,8 @@  public:
 private:
 	LIBCAMERA_DISABLE_COPY_AND_MOVE(eGL)
 
+	static EGLDisplay probeDisplay();
+
 	pid_t tid_;
 
 	EGLDisplay display_ = EGL_NO_DISPLAY;
diff --git a/src/libcamera/egl.cpp b/src/libcamera/egl.cpp
index c185bb7a..860f18dd 100644
--- a/src/libcamera/egl.cpp
+++ b/src/libcamera/egl.cpp
@@ -267,6 +267,50 @@  void eGL::createTexture2D(eGLImage &eglImage, void *data)
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 }
 
+EGLDisplay eGL::probeDisplay()
+{
+	EGLDisplay display;
+
+	if (!eglBindAPI(EGL_OPENGL_ES_API)) {
+		LOG(eGL, Info) << "API bind fail";
+		return EGL_NO_DISPLAY;
+	}
+
+	display = eglGetPlatformDisplay(EGL_PLATFORM_SURFACELESS_MESA,
+					 EGL_DEFAULT_DISPLAY,
+					 nullptr);
+
+	if (display == EGL_NO_DISPLAY) {
+		LOG(eGL, Info) << "Unable to get EGL display";
+		return EGL_NO_DISPLAY;
+	}
+
+	if (eglInitialize(display, nullptr, nullptr) != EGL_TRUE) {
+		LOG(eGL, Error) << "eglInitialize fail";
+		return EGL_NO_DISPLAY;
+	}
+
+	return display;
+}
+
+/**
+ * \brief Probe whether EGL surfaceless rendering is available
+ *
+ * Checks if an EGL surfaceless display can be obtained and initialised.
+ * The display is immediately terminated so that no resources are leaked.
+ *
+ * \return true if EGL surfaceless rendering is available, false otherwise
+ */
+bool eGL::isAvailable()
+{
+	EGLDisplay display = probeDisplay();
+	if (display == EGL_NO_DISPLAY)
+		return false;
+
+	eglTerminate(display);
+	return true;
+}
+
 /**
  * \brief Initialise the EGL context
  *
@@ -297,21 +341,9 @@  int eGL::initEGLContext()
 	EGLint numConfigs;
 	EGLConfig config;
 
-	if (!eglBindAPI(EGL_OPENGL_ES_API)) {
-		LOG(eGL, Error) << "API bind fail";
-		goto fail;
-	}
-
-	display_ = eglGetPlatformDisplay(EGL_PLATFORM_SURFACELESS_MESA,
-					 EGL_DEFAULT_DISPLAY,
-					 nullptr);
+	display_ = probeDisplay();
 	if (display_ == EGL_NO_DISPLAY) {
-		LOG(eGL, Error) << "Unable to get EGL display";
-		goto fail;
-	}
-
-	if (eglInitialize(display_, nullptr, nullptr) != EGL_TRUE) {
-		LOG(eGL, Error) << "eglInitialize fail";
+		LOG(eGL, Error) << "Unable to probe display";
 		goto fail;
 	}
 
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index 781cf02f..ff8c3465 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -119,8 +119,14 @@  SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const CameraSensor *sensor,
 		}
 	}
 
-	if (!softISPMode || softISPMode == "gpu")
-		debayer_ = std::make_unique<DebayerEGL>(std::move(stats), cm);
+	if (!softISPMode || softISPMode == "gpu") {
+		if (eGL::isAvailable()) {
+			debayer_ = std::make_unique<DebayerEGL>(std::move(stats), cm);
+		} else {
+			LOG(SoftwareIsp, Info)
+				<< "EGL not available, falling back to CPU debayer";
+		}
+	}
 
 #endif
 	if (!debayer_)