1
0
forked from pool/libqt5-qtbase
libqt5-qtbase/0003-Revert-White-list-more-recent-Mesa-version-for-multi.patch

103 lines
4.4 KiB
Diff

From e0bf494295398cbc3ba5a84380525f9c00e3f8ad Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fabian@ritter-vogt.de>
Date: Thu, 14 Mar 2019 10:32:16 +0100
Subject: [PATCH 3/3] Revert "White-list more recent Mesa version for
multi-threading"
This reverts commit 97600d2c2885e667ced0926815b5a12a7f25285c.
---
.../xcb_glx/qglxintegration.cpp | 60 +++++++++++--------
1 file changed, 35 insertions(+), 25 deletions(-)
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
index ddb8f45188..41012c0b04 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
@@ -48,7 +48,6 @@
#undef register
#include <GL/glx.h>
-#include <QtCore/QRegularExpression>
#include <QtGui/QOpenGLContext>
#include <QtGui/QOffscreenSurface>
@@ -650,6 +649,32 @@ static const char *qglx_threadedgl_blacklist_renderer[] = {
0
};
+// This disables threaded rendering on anything using mesa, e.g.
+// - nvidia/nouveau
+// - amd/gallium
+// - intel
+// - some software opengl implementations
+//
+// The client glx vendor string is used to identify those setups as that seems to show the least
+// variance between the bad configurations. It's always "Mesa Project and SGI". There are some
+// configurations which don't use mesa and which can do threaded rendering (amd and nvidia chips
+// with their own proprietary drivers).
+//
+// This, of course, is very broad and disables threaded rendering on a lot of devices which would
+// be able to use it. However, the bugs listed below don't follow any easily recognizable pattern
+// and we should rather be safe.
+//
+// http://cgit.freedesktop.org/xcb/libxcb/commit/?id=be0fe56c3bcad5124dcc6c47a2fad01acd16f71a will
+// fix some of the issues. Basically, the proprietary drivers seem to have a way of working around
+// a fundamental flaw with multithreaded access to xcb, but mesa doesn't. The blacklist should be
+// reevaluated once that patch is released in some version of xcb.
+static const char *qglx_threadedgl_blacklist_vendor[] = {
+ "Mesa Project and SGI", // QTCREATORBUG-10875 (crash in creator)
+ // QTBUG-34492 (flickering in fullscreen)
+ // QTBUG-38221
+ 0
+};
+
void QGLXContext::queryDummyContext()
{
if (m_queriedDummyContext)
@@ -709,33 +734,18 @@ void QGLXContext::queryDummyContext()
}
}
- if (glxvendor && m_supportsThreading) {
- // Blacklist Mesa drivers due to QTCREATORBUG-10875 (crash in creator),
- // QTBUG-34492 (flickering in fullscreen) and QTBUG-38221
- const char *mesaVersionStr = nullptr;
- if (strstr(glxvendor, "Mesa Project") != 0) {
- mesaVersionStr = (const char *) glGetString(GL_VERSION);
- m_supportsThreading = false;
- }
+ if (glxvendor) {
+ for (int i = 0; qglx_threadedgl_blacklist_vendor[i]; ++i) {
+ if (strstr(glxvendor, qglx_threadedgl_blacklist_vendor[i]) != 0) {
+ qCDebug(lcQpaGl).nospace() << "Multithreaded OpenGL disabled: "
+ "blacklisted vendor \""
+ << qglx_threadedgl_blacklist_vendor[i]
+ << "\"";
- if (mesaVersionStr) {
- // The issue was fixed in Xcb 1.11, but we can't check for that
- // at runtime, so instead assume it fixed with recent Mesa versions
- // released several years after the Xcb fix.
- QRegularExpression versionTest(QStringLiteral("Mesa (\\d+)"));
- QRegularExpressionMatch result = versionTest.match(QString::fromLatin1(mesaVersionStr));
- int versionNr = 0;
- if (result.hasMatch())
- versionNr = result.captured(1).toInt();
- if (versionNr >= 17) {
- // White-listed
- m_supportsThreading = true;
+ m_supportsThreading = false;
+ break;
}
}
- if (!m_supportsThreading) {
- qCDebug(lcQpaGl).nospace() << "Multithreaded OpenGL disabled: "
- "blacklisted vendor \"Mesa Project\"";
- }
}
context.doneCurrent();
--
2.20.1