texturing: add a test for GPU/CPU sync when creating textures

On Panfrost, at least, a race condition could occur if a texture
is cleared and then initialized with texSubImage; the clear on
the GPU could happen after the memcpy in texSubImage. This test
checks for that and triggers the original Panfrost bug.

Signed-off-by: Eric R. Smith <eric.smith@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/piglit/-/merge_requests/901>

3 files changed, 104 insertions, 0 deletions

diff --git a/tests/opengl.py b/tests/opengl.py
index 2ce58bb90..b9bd17a9d 100644
--- a/tests/opengl.py
+++ b/tests/opengl.py
@@ -947,6 +947,7 @@ with profile.test_list.group_manager(
     g(['generatemipmap-base-change', 'format'])
     g(['generatemipmap-cubemap'])
     g(['viewport-clamp'])
+    g(['texsubimage-sync'])
 
 with profile.test_list.group_manager(
         PiglitGLTest,
diff --git a/tests/texturing/CMakeLists.gl.txt b/tests/texturing/CMakeLists.gl.txt
index 02b572c79..c56eeaf46 100644
--- a/tests/texturing/CMakeLists.gl.txt
+++ b/tests/texturing/CMakeLists.gl.txt
@@ -77,6 +77,7 @@ piglit_add_executable (texdepth texdepth.c)
 piglit_add_executable (teximage-errors teximage-errors.c)
 piglit_add_executable (texrect-many texrect-many.c)
 piglit_add_executable (texredefine texredefine.c)
+piglit_add_executable (texsubimage-sync texsubimage-sync.c)
 piglit_add_executable (texture-packed-formats texture-packed-formats.c)
 piglit_add_executable (texwrap texwrap.c)
 piglit_add_executable (depth-tex-modes      depth-tex-modes.c depth-tex-modes-common.c)
diff --git a/tests/texturing/texsubimage-sync.c b/tests/texturing/texsubimage-sync.c
new file mode 100644
index 000000000..3bff88503
--- /dev/null
+++ b/tests/texturing/texsubimage-sync.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright © 2024 Collabora Ltd
+ * SPDX-License-Identifier: MIT
+ *
+ * Test for clear before render in texture preparation
+ * If the texture is small and we use memcpy in
+ * TexSubImage2D then that can complete before the clear,
+ * which means that if the driver doesn't synchronize the
+ * GPU and CPU properly the clear can overwrite the texture data.
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 30;
+
+	config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static GLuint
+create_texture(GLsizei w, GLsizei h)
+{
+	GLuint tex, fbo;
+	GLint i;
+	static GLfloat red[] = { 1.0, 0, 0, 1.0 };
+
+	/* prepare a blob filled with green and max alpha */
+	GLubyte *colorblob = calloc(4, w * h);
+	for (i = 1; i < w*h*4; i += 2) {
+		colorblob[i] = 0xff;
+	}
+
+	/* get a framebuffer for the texture */
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+	/* create texture */
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D, tex);
+	glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, w, h);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	/* use ClearBuffer to fill with red (likely on the GPU) */
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex, 0);
+	glClearBufferfv(GL_COLOR, 0, red);
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	glDeleteFramebuffers(1, &fbo);
+
+	/* now fill with green via TexSubImage2D (possibly on the CPU) */
+	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, colorblob);
+	glBindTexture(GL_TEXTURE_2D, 0);
+
+	free(colorblob);
+
+	return tex;
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	static const GLfloat green[3] = {0.0, 1.0, 0.0};
+	GLboolean pass = GL_TRUE;
+	GLuint tex;
+
+	/* clear frame buffer */
+	glClearColor(0.0, 0.0, 0.0, 0.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	/* create a small texture */
+	tex = create_texture(4, 4);
+
+	/* draw with it */
+	glBindTexture(GL_TEXTURE_2D, tex);
+	glEnable(GL_TEXTURE_2D);
+	piglit_draw_rect_tex(0, 0, piglit_width, piglit_height, 0, 0, 1, 1);
+
+	/* check for expected values */
+	pass = pass && piglit_probe_rect_rgb(0, 0, piglit_width, piglit_height, green);
+
+	/* show on screen */
+	piglit_present_results();
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	glDisable(GL_DITHER);
+
+	glMatrixMode( GL_PROJECTION );
+	glPushMatrix();
+	glLoadIdentity();
+	glOrtho( 0, piglit_width, 0, piglit_height, -1, 1 );
+
+	glMatrixMode( GL_MODELVIEW );
+	glPushMatrix();
+	glLoadIdentity();
+}