[v3,1/2] egl: Use the Mesa surfaceless platform instead of GBM
diff mbox series

Message ID 20260120122344.28283-1-robert.mader@collabora.com
State New
Headers show
Series
  • [v3,1/2] egl: Use the Mesa surfaceless platform instead of GBM
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Commit Message

Robert Mader Jan. 20, 2026, 12:23 p.m. UTC 
Mesa surfaceless platform appears to be a better fit for the use-case at hand:
1. Like GBM it is Mesa specific, so no change in supported setups is
   expected. If ever required, a fallback to the generic device platform
   could be added on top.
2. It leaves the complexity of selecting a renderer device to the
   driver, reducing code and dependencies.
3. It allows to use llvmpipe / software drivers without dri device,
   which can be useful on CI or debugging (with LIBGL_ALWAYS_SOFTWARE=1).

Signed-off-by: Robert Mader <robert.mader@collabora.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # sm8250/rb5, x1e/Dell Insprion14p
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Tested-by: Milan Zamazal <mzamazal@redhat.com> # TI AM69
Tested-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> # ThinkPad X1 Yoga Gen 7 + ov2740
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---

Changes in v3:
 - Minor commit message improvement
 - Use EGL_DEFAULT_DISPLAY instead of nullptr (no change in behavior)
 - Improve comment formating
 - Add Laurents R-B

Changes in v2:
 - Add tags
---
 include/libcamera/internal/egl.h           |  4 +---
 src/libcamera/egl.cpp                      | 14 +++++++-------
 src/libcamera/software_isp/debayer_egl.cpp |  9 +++------
 src/libcamera/software_isp/debayer_egl.h   |  1 -
 4 files changed, 11 insertions(+), 17 deletions(-)

Patch
diff mbox series 

diff --git a/include/libcamera/internal/egl.h b/include/libcamera/internal/egl.h
index f007f448a..630345ea7 100644
--- a/include/libcamera/internal/egl.h
+++ b/include/libcamera/internal/egl.h
@@ -16,8 +16,6 @@ 
 #include <libcamera/base/span.h>
 #include <libcamera/base/utils.h>
 
-#include "libcamera/internal/gbm.h"
-
 #define EGL_EGLEXT_PROTOTYPES
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
@@ -96,7 +94,7 @@  public:
 	eGL();
 	~eGL();
 
-	int initEGLContext(GBM *gbmContext);
+	int initEGLContext();
 
 	int createInputDMABufTexture2D(eGLImage &eglImage, int fd);
 	int createOutputDMABufTexture2D(eGLImage &eglImage, int fd);
diff --git a/src/libcamera/egl.cpp b/src/libcamera/egl.cpp
index da563ee09..5b9bbf410 100644
--- a/src/libcamera/egl.cpp
+++ b/src/libcamera/egl.cpp
@@ -256,24 +256,22 @@  void eGL::createTexture2D(eGLImage &eglImage, GLint format, uint32_t width, uint
 
 /**
  * \brief Initialise the EGL context
- * \param[in] gbmContext Pointer to initialised GBM context
  *
- * Sets up the EGL display from the GBM device, creates an OpenGL ES 2.0
- * context, and retrieves function pointers for required extensions
- * including:
+ * Sets up the EGL display, creates an OpenGL ES 2.0 context, and retrieves
+ * function pointers for required extensions including:
  * - eglCreateImageKHR / eglDestroyImageKHR
  * - glEGLImageTargetTexture2DOES
  *
  * \return 0 on success, or -ENODEV on failure
  */
-int eGL::initEGLContext(GBM *gbmContext)
+int eGL::initEGLContext()
 {
 	EGLint configAttribs[] = {
 		EGL_RED_SIZE, 8,
 		EGL_GREEN_SIZE, 8,
 		EGL_BLUE_SIZE, 8,
 		EGL_ALPHA_SIZE, 8,
-		EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+		EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
 		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
 		EGL_NONE
 	};
@@ -291,7 +289,9 @@  int eGL::initEGLContext(GBM *gbmContext)
 		goto fail;
 	}
 
-	display_ = eglGetDisplay(gbmContext->device());
+	display_ = eglGetPlatformDisplay(EGL_PLATFORM_SURFACELESS_MESA,
+					 EGL_DEFAULT_DISPLAY,
+					 nullptr);
 	if (display_ == EGL_NO_DISPLAY) {
 		LOG(eGL, Error) << "Unable to get EGL display";
 		goto fail;
diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp
index 9693d7252..37c44e8b1 100644
--- a/src/libcamera/software_isp/debayer_egl.cpp
+++ b/src/libcamera/software_isp/debayer_egl.cpp
@@ -141,8 +141,8 @@  int DebayerEGL::initBayerShaders(PixelFormat inputFormat, PixelFormat outputForm
 	egl_.pushEnv(shaderEnv, "#extension GL_OES_EGL_image_external: enable");
 
 	/*
-	 * Tell shaders how to re-order output taking account of how the
-	 * pixels are actually stored by GBM
+	 * Tell shaders how to re-order output taking account of how the pixels
+	 * are actually stored by EGL.
 	 */
 	switch (outputFormat) {
 	case formats::ARGB8888:
@@ -586,10 +586,7 @@  int DebayerEGL::start()
 {
 	GLint maxTextureImageUnits;
 
-	if (gbmSurface_.createDevice())
-		return -ENODEV;
-
-	if (egl_.initEGLContext(&gbmSurface_))
+	if (egl_.initEGLContext())
 		return -ENODEV;
 
 	glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &maxTextureImageUnits);
diff --git a/src/libcamera/software_isp/debayer_egl.h b/src/libcamera/software_isp/debayer_egl.h
index a5033bc63..cfbaf8e9d 100644
--- a/src/libcamera/software_isp/debayer_egl.h
+++ b/src/libcamera/software_isp/debayer_egl.h
@@ -113,7 +113,6 @@  private:
 	Rectangle window_;
 	std::unique_ptr<SwStatsCpu> stats_;
 	eGL egl_;
-	GBM gbmSurface_;
 	uint32_t width_;
 	uint32_t height_;
 	GLint glFormat_;