From 3bb3ee936f27e9749bf1a2c4bd5ded2f5167663f Mon Sep 17 00:00:00 2001 From: Max Staudt Date: Mon, 12 Feb 2018 15:07:29 +0100 Subject: [PATCH] opengl: Bail if cached shader fails to load References: boo#1080578, boo#1079465 Signed-off-by: Max Staudt QOpenGLProgramBinaryCache::setProgramBinary() should check GL_LINK_STATUS after glProgramBinary(), but doesn't. In practice, this means that SDDM is a white screen, and KDE is just a gray task bar. So far, Qt tries to check this using its internal ::link() function. But in case the cached binary fails to load, Qt currently attempts to link the inexistent program, resulting in a zero-length, fixed pipeline shader. Checking this already in ::setProgramBinary() makes the call to ::link() superfluous, so we remove that as well. Many thanks to Michal Srb and Fabian Vogt for hunting this down. This was truly a joint effort. Cc: Michal Srb Cc: Fabian Vogt Signed-off-by: Max Staudt --- src/gui/opengl/qopenglprogrambinarycache.cpp | 11 ++++++++++- src/gui/opengl/qopenglshaderprogram.cpp | 8 +------- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/src/gui/opengl/qopenglprogrambinarycache.cpp b/src/gui/opengl/qopenglprogrambinarycache.cpp index 06373e1113..f50878ab5c 100644 --- a/src/gui/opengl/qopenglprogrambinarycache.cpp +++ b/src/gui/opengl/qopenglprogrambinarycache.cpp @@ -161,10 +161,19 @@ bool QOpenGLProgramBinaryCache::setProgramBinary(uint programId, uint blobFormat QOpenGLExtraFunctions *funcs = QOpenGLContext::currentContext()->extraFunctions(); while (funcs->glGetError() != GL_NO_ERROR) { } funcs->glProgramBinary(programId, blobFormat, p, blobSize); + int err = funcs->glGetError(); + GLint link_status = 0; + funcs->glGetProgramiv(programId, GL_LINK_STATUS, &link_status); + if (link_status != GL_TRUE || err != GL_NO_ERROR) { + qCDebug(DBG_SHADER_CACHE, "Program binary failed to load for program %u, size %d, format 0x%x, link_status = 0x%x, err = 0x%x", + programId, blobSize, blobFormat, link_status, err); + return false; + } + qCDebug(DBG_SHADER_CACHE, "Program binary set for program %u, size %d, format 0x%x, err = 0x%x", programId, blobSize, blobFormat, err); - return err == 0; + return true; } #ifdef Q_OS_UNIX diff --git a/src/gui/opengl/qopenglshaderprogram.cpp b/src/gui/opengl/qopenglshaderprogram.cpp index cc8af16bfe..3b82baccb3 100644 --- a/src/gui/opengl/qopenglshaderprogram.cpp +++ b/src/gui/opengl/qopenglshaderprogram.cpp @@ -3824,13 +3824,7 @@ bool QOpenGLShaderProgramPrivate::linkBinary() bool needsCompile = true; if (binCache.load(cacheKey, q->programId())) { qCDebug(DBG_SHADER_CACHE, "Program binary received from cache"); - linkBinaryRecursion = true; - bool ok = q->link(); - linkBinaryRecursion = false; - if (ok) - needsCompile = false; - else - qCDebug(DBG_SHADER_CACHE, "Link failed after glProgramBinary"); + needsCompile = false; } bool needsSave = false; -- 2.13.6