Merge commit 'origin/master' into drm-gem

Conflicts:

	src/mesa/drivers/dri/common/dri_bufmgr.h
	src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
	src/mesa/drivers/dri/intel/intel_bufmgr_ttm.h
	src/mesa/drivers/dri/intel/intel_ioctl.c

20 files changed, 395 insertions, 39 deletions

diff --git a/progs/Makefile b/progs/Makefile
index 5e705efa7e..c99f4eebcc 100644
--- a/progs/Makefile
+++ b/progs/Makefile
@@ -25,7 +25,7 @@ subdirs:
 install:
 
 clean:
-	@for dir in $(SUBDIRS) tests ; do \
+	-@for dir in $(SUBDIRS) tests ; do \
 		if [ -d $$dir ] ; then \
 			(cd $$dir && $(MAKE) clean) ; \
 		fi \
diff --git a/progs/beos/Makefile b/progs/beos/Makefile
index 491e8e442d..0dc4cdce63 100644
--- a/progs/beos/Makefile
+++ b/progs/beos/Makefile
@@ -19,8 +19,8 @@ INCLUDES = -I. -I- -I../../include
 default: demo sample GLInfo
 
 clean:
-	rm -f demo sample GLInfo
-	rm -f *.o
+	-rm -f demo sample GLInfo
+	-rm -f *.o
 
 demo: demo.o
 	$(LD) demo.o $(LDFLAGS) $(LIBS) -o $@
diff --git a/progs/demos/Makefile b/progs/demos/Makefile
index 01b76ad105..7fde77f0b4 100644
--- a/progs/demos/Makefile
+++ b/progs/demos/Makefile
@@ -11,9 +11,11 @@ OSMESA16_LIBS = -L$(TOP)/$(LIB_DIR) -lglut -lOSMesa16 -lGLU -lGL $(APP_LIB_DEPS)
 
 OSMESA32_LIBS = -L$(TOP)/$(LIB_DIR) -lglut -lOSMesa32 -lGLU -lGL $(APP_LIB_DEPS)
 
-LIB_DEP = $(TOP)/$(LIB_DIR)/$(GL_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLU_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLUT_LIB_NAME)
+LIB_DEP = $(TOP)/$(LIB_DIR)/$(GL_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLU_LIB_NAME) \
+	$(TOP)/$(LIB_DIR)/$(GLUT_LIB_NAME)
 
-LIBS = -L$(TOP)/$(LIB_DIR) -l$(GLUT_LIB) -l$(GLU_LIB) -l$(GL_LIB) $(APP_LIB_DEPS) -lX11  -lXi -lXmu
+LIBS = -L$(TOP)/$(LIB_DIR) -l$(GLUT_LIB) -l$(GLU_LIB) -l$(GL_LIB) \
+	$(APP_LIB_DEPS)
 
 PROGS = \
 	arbfplight \
diff --git a/progs/egl/Makefile b/progs/egl/Makefile
index 07215604d3..416d2c04b2 100644
--- a/progs/egl/Makefile
+++ b/progs/egl/Makefile
@@ -60,6 +60,6 @@ eglgears.o: eglgears.c $(HEADERS)
 
 
 clean:
-	rm -f *.o *~
-	rm -f *.so
-	rm -f $(PROGRAMS)
+	-rm -f *.o *~
+	-rm -f *.so
+	-rm -f $(PROGRAMS)
diff --git a/progs/fbdev/Makefile b/progs/fbdev/Makefile
index 56daf56f8a..39401243e5 100644
--- a/progs/fbdev/Makefile
+++ b/progs/fbdev/Makefile
@@ -37,8 +37,8 @@ LIBS = -L$(TOP)/$(LIB_DIR) -l$(GLU_LIB) -l$(GL_LIB) $(APP_LIB_DEPS)
 default:  depend $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
+	-rm -f $(PROGS)
+	-rm -f *.o
 
 
 depend: $(SOURCES)
diff --git a/progs/fp/Makefile b/progs/fp/Makefile
index a395b734ef..09f22d1a7b 100644
--- a/progs/fp/Makefile
+++ b/progs/fp/Makefile
@@ -86,9 +86,9 @@ UTIL_FILES = readtex.h readtex.c
 default: $(UTIL_FILES) $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
-	rm -f getproclist.h
+	-rm -f $(PROGS)
+	-rm -f *.o
+	-rm -f getproclist.h
 
 
 # auto code generation
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
index ff8fbeb99b..e3f205cdb9 100644
--- a/progs/glsl/Makefile
+++ b/progs/glsl/Makefile
@@ -15,6 +15,7 @@ PROGS = \
 	bump \
 	deriv \
 	mandelbrot \
+	multitex \
 	noise \
 	points \
 	texdemo1 \
@@ -102,6 +103,13 @@ mandelbrot: mandelbrot.o shaderutil.o
 	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) mandelbrot.o shaderutil.o $(LIBS) -o $@
 
 
+multitex.o: multitex.c extfuncs.h readtex.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) multitex.c
+
+multitex: multitex.o readtex.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) multitex.o readtex.o shaderutil.o $(LIBS) -o $@
+
+
 noise.o: noise.c extfuncs.h shaderutil.h
 	$(CC) -c -I$(INCDIR) $(CFLAGS) noise.c
 
diff --git a/progs/glsl/multitex.c b/progs/glsl/multitex.c
new file mode 100644
index 0000000000..5574ed4139
--- /dev/null
+++ b/progs/glsl/multitex.c
@@ -0,0 +1,285 @@
+/**
+ * Test multi-texturing with GL shading language.
+ *
+ * Copyright (C) 2008  Brian Paul   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "GL/glut.h"
+#include "readtex.h"
+#include "extfuncs.h"
+#include "shaderutil.h"
+
+static const char *Demo = "multitex";
+
+static const char *VertFile = "multitex.vert.txt";
+static const char *FragFile = "multitex.frag.txt";
+
+static const char *TexFiles[2] = 
+   {
+      "../images/tile.rgb",
+      "../images/tree2.rgba"
+   };
+
+
+static GLuint Program;
+
+static GLfloat Xrot = -90.0, Yrot = .0, Zrot = 0.0;
+static GLfloat EyeDist = 10;
+static GLboolean Anim = GL_TRUE;
+
+
+/* value[0] = tex unit */
+static struct uniform_info Uniforms[] = {
+   { "tex1",  1, GL_INT, { 0, 0, 0, 0 }, -1 },
+   { "tex2",  1, GL_INT, { 1, 0, 0, 0 }, -1 },
+   END_OF_UNIFORMS
+};
+
+
+static void
+DrawPolygon(GLfloat size)
+{
+   glPushMatrix();
+   glRotatef(90, 1, 0, 0);
+   glNormal3f(0, 0, 1);
+   glBegin(GL_POLYGON);
+
+   glMultiTexCoord2f(GL_TEXTURE0, 0, 0);
+   glMultiTexCoord2f(GL_TEXTURE1, 0, 0);
+   glVertex2f(-size, -size);
+
+   glMultiTexCoord2f(GL_TEXTURE0, 2, 0);
+   glMultiTexCoord2f(GL_TEXTURE1, 1, 0);
+   glVertex2f( size, -size);
+
+   glMultiTexCoord2f(GL_TEXTURE0, 2, 2);
+   glMultiTexCoord2f(GL_TEXTURE1, 1, 1);
+   glVertex2f( size,  size);
+
+   glMultiTexCoord2f(GL_TEXTURE0, 0, 2);
+   glMultiTexCoord2f(GL_TEXTURE1, 0, 1);
+   glVertex2f(-size,  size);
+
+   glEnd();
+   glPopMatrix();
+}
+
+
+static void
+draw(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   glPushMatrix(); /* modelview matrix */
+      glTranslatef(0.0, 0.0, -EyeDist);
+      glRotatef(Zrot, 0, 0, 1);
+      glRotatef(Yrot, 0, 1, 0);
+      glRotatef(Xrot, 1, 0, 0);
+
+      DrawPolygon(3.0);
+
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+static void
+idle(void)
+{
+   GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
+   Yrot = t;
+   glutPostRedisplay();
+}
+
+
+static void
+key(unsigned char k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+   case ' ':
+   case 'a':
+      Anim = !Anim;
+      if (Anim)
+         glutIdleFunc(idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   case 'z':
+      EyeDist -= 0.5;
+      if (EyeDist < 3.0)
+         EyeDist = 3.0;
+      break;
+   case 'Z':
+      EyeDist += 0.5;
+      if (EyeDist > 90.0)
+         EyeDist = 90;
+      break;
+   case 27:
+      exit(0);
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+specialkey(int key, int x, int y)
+{
+   GLfloat step = 2.0;
+   (void) x;
+   (void) y;
+   switch (key) {
+   case GLUT_KEY_UP:
+      Xrot += step;
+      break;
+   case GLUT_KEY_DOWN:
+      Xrot -= step;
+      break;
+   case GLUT_KEY_LEFT:
+      Yrot -= step;
+      break;
+   case GLUT_KEY_RIGHT:
+      Yrot += step;
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+/* new window size or exposure */
+static void
+Reshape(int width, int height)
+{
+   GLfloat ar = (float) width / (float) height;
+   glViewport(0, 0, (GLint)width, (GLint)height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+}
+
+
+static void
+InitTextures(void)
+{
+   GLenum filter = GL_LINEAR;
+   int i;
+
+   for (i = 0; i < 2; i++) {
+      GLint imgWidth, imgHeight;
+      GLenum imgFormat;
+      GLubyte *image = NULL;
+
+      image = LoadRGBImage(TexFiles[i], &imgWidth, &imgHeight, &imgFormat);
+      if (!image) {
+         printf("Couldn't read %s\n", TexFiles[i]);
+         exit(0);
+      }
+
+      glActiveTexture(GL_TEXTURE0 + i);
+      glBindTexture(GL_TEXTURE_2D, 42 + i);
+      gluBuild2DMipmaps(GL_TEXTURE_2D, 4, imgWidth, imgHeight,
+                        imgFormat, GL_UNSIGNED_BYTE, image);
+      free(image);
+      
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
+   }
+}
+
+
+static GLuint
+CreateProgram(const char *vertProgFile, const char *fragProgFile,
+              struct uniform_info *uniforms)
+{
+   GLuint fragShader, vertShader, program;
+
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
+   assert(vertShader);
+   program = LinkShaders(vertShader, fragShader);
+
+   glUseProgram_func(program);
+
+   InitUniforms(program, uniforms);
+
+   return program;
+}
+
+
+static void
+InitPrograms(void)
+{
+   Program = CreateProgram(VertFile, FragFile, Uniforms);
+}
+
+
+static void
+InitGL(void)
+{
+   const char *version = (const char *) glGetString(GL_VERSION);
+
+   if (version[0] != '2' || version[1] != '.') {
+      printf("Warning: this program expects OpenGL 2.0\n");
+      /*exit(1);*/
+   }
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   GetExtensionFuncs();
+
+   InitTextures();
+   InitPrograms();
+
+   glEnable(GL_DEPTH_TEST);
+
+   glClearColor(.6, .6, .9, 0);
+   glColor3f(1.0, 1.0, 1.0);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowSize(500, 400);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+   glutCreateWindow(Demo);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(key);
+   glutSpecialFunc(specialkey);
+   glutDisplayFunc(draw);
+   if (Anim)
+      glutIdleFunc(idle);
+   InitGL();
+   glutMainLoop();
+   return 0;
+}
diff --git a/progs/glsl/multitex.frag.txt b/progs/glsl/multitex.frag.txt
new file mode 100644
index 0000000000..86045306af
--- /dev/null
+++ b/progs/glsl/multitex.frag.txt
@@ -0,0 +1,15 @@
+// Multi-texture fragment shader
+// Brian Paul
+
+// Composite second texture over first.
+// We're assuming the 2nd texture has a meaningful alpha channel.
+
+uniform sampler2D tex1;
+uniform sampler2D tex2;
+
+void main()
+{
+   vec4 t1 = texture2D(tex1, gl_TexCoord[0].xy, 0.0);
+   vec4 t2 = texture2D(tex2, gl_TexCoord[1].xy, 0.0);
+   gl_FragColor = mix(t1, t2, t2.w);
+}
diff --git a/progs/glsl/multitex.vert.txt b/progs/glsl/multitex.vert.txt
new file mode 100644
index 0000000000..5518ca1ddd
--- /dev/null
+++ b/progs/glsl/multitex.vert.txt
@@ -0,0 +1,10 @@
+// Multi-texture vertex shader
+// Brian Paul
+
+
+void main() 
+{
+   gl_TexCoord[0] = gl_MultiTexCoord0;
+   gl_TexCoord[1] = gl_MultiTexCoord1;
+   gl_Position = ftransform();
+}
diff --git a/progs/miniglx/Makefile b/progs/miniglx/Makefile
index 5d0c8eae64..d5258b0a96 100644
--- a/progs/miniglx/Makefile
+++ b/progs/miniglx/Makefile
@@ -43,8 +43,8 @@ LIBS = -L$(TOP)/$(LIB_DIR) -l$(GLUT_LIB) -l$(GLU_LIB) -l$(GL_LIB) $(APP_LIB_DEPS
 default:  depend $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
+	-rm -f $(PROGS)
+	-rm -f *.o
 
 
 depend: $(SOURCES)
diff --git a/progs/slang/Makefile b/progs/slang/Makefile
index ea1e9b6afd..c93caeab61 100644
--- a/progs/slang/Makefile
+++ b/progs/slang/Makefile
@@ -24,7 +24,7 @@ tests: default
 	! ./cltest 2> /dev/null | (grep -e ^[*][*][*])
 
 clean:
-	rm -f cltest.o sotest.o vstest.o framework.o cltest sotest vstest
+	-rm -f cltest.o sotest.o vstest.o framework.o cltest sotest vstest
 
 #
 # executables
diff --git a/progs/tests/Makefile b/progs/tests/Makefile
index 116a19b1f5..cf8e0bfc1e 100644
--- a/progs/tests/Makefile
+++ b/progs/tests/Makefile
@@ -99,9 +99,9 @@ UTIL_FILES = readtex.h readtex.c
 default: $(UTIL_FILES) $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
-	rm -f getproclist.h
+	-rm -f $(PROGS)
+	-rm -f *.o
+	-rm -f getproclist.h
 
 ##### RULES #####
 
diff --git a/progs/tests/fbotest2.c b/progs/tests/fbotest2.c
index 18f28972b6..5283c7e1fd 100644
--- a/progs/tests/fbotest2.c
+++ b/progs/tests/fbotest2.c
@@ -68,6 +68,7 @@ Display( void )
 
    /* draw to window */
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+   glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
    glWindowPos2iARB(0, 0);
    glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
 
diff --git a/progs/tests/mipmap_limits.c b/progs/tests/mipmap_limits.c
index d6d6e467b0..8bdad826f7 100644
--- a/progs/tests/mipmap_limits.c
+++ b/progs/tests/mipmap_limits.c
@@ -59,6 +59,18 @@ static GLfloat LodBias = 0.0;
 static GLboolean NearestFilter = GL_TRUE;
 
 
+static void
+InitValues(void)
+{
+   BaseLevel = 0;
+   MaxLevel = 8;
+   MinLod = -1;
+   MaxLod = 9;
+   LodBias = 0.0;
+   NearestFilter = GL_TRUE;
+}
+
+
 static void MakeImage(int level, int width, int height, const GLubyte color[4])
 {
    const int makeStripes = 0;
@@ -108,6 +120,8 @@ static void makeImages(void)
 
 static void myinit(void)
 {
+    InitValues();
+
     glEnable(GL_DEPTH_TEST);
     glDepthFunc(GL_LESS);
     glShadeModel(GL_FLAT);
@@ -125,7 +139,7 @@ static void myinit(void)
 static void display(void)
 {
    GLfloat tcm = 4.0;
-    printf("BASE_LEVEL = %d  MAX_LEVEL = %d  MIN_LOD = %f MAX_LOD = %f Bias = %.2g  filter = %s\n",
+    printf("BASE_LEVEL=%d  MAX_LEVEL=%d  MIN_LOD=%.2g  MAX_LOD=%.2g  Bias=%.2g  Filter=%s\n",
            BaseLevel, MaxLevel, MinLod, MaxLod, LodBias,
            NearestFilter ? "NEAREST" : "LINEAR");
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
@@ -214,6 +228,9 @@ key(unsigned char k, int x, int y)
   case 'f':
      NearestFilter = !NearestFilter;
      break;
+  case ' ':
+     InitValues();
+     break;
   case 27:  /* Escape */
     exit(0);
     break;
@@ -227,12 +244,13 @@ key(unsigned char k, int x, int y)
 static void usage(void)
 {
    printf("usage:\n");
-   printf("  b/B  decrease/increase GL_TEXTURE_BASE_LEVEL\n");
-   printf("  m/M  decrease/increase GL_TEXTURE_MAX_LEVEL\n");
-   printf("  n/N  decrease/increase GL_TEXTURE_MIN_LOD\n");
-   printf("  x/X  decrease/increase GL_TEXTURE_MAX_LOD\n");
-   printf("  l/L  decrease/increase GL_TEXTURE_LOD_BIAS\n");
-   printf("  f    toggle nearest/linear filtering\n");
+   printf("  b/B    decrease/increase GL_TEXTURE_BASE_LEVEL\n");
+   printf("  m/M    decrease/increase GL_TEXTURE_MAX_LEVEL\n");
+   printf("  n/N    decrease/increase GL_TEXTURE_MIN_LOD\n");
+   printf("  x/X    decrease/increase GL_TEXTURE_MAX_LOD\n");
+   printf("  l/L    decrease/increase GL_TEXTURE_LOD_BIAS\n");
+   printf("  f      toggle nearest/linear filtering\n");
+   printf("  SPACE  reset values\n");
 }
 
 
diff --git a/progs/trivial/Makefile b/progs/trivial/Makefile
index 7610a5df08..6fa51ce2cf 100644
--- a/progs/trivial/Makefile
+++ b/progs/trivial/Makefile
@@ -102,9 +102,9 @@ UTIL_FILES = readtex.h readtex.c
 default: $(UTIL_FILES) $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
-	rm -f getproclist.h
+	-rm -f $(PROGS)
+	-rm -f *.o
+	-rm -f getproclist.h
 
 
 # auto code generation
diff --git a/progs/trivial/tri.c b/progs/trivial/tri.c
index 58a650b559..d4a7f08ae3 100644
--- a/progs/trivial/tri.c
+++ b/progs/trivial/tri.c
@@ -33,6 +33,7 @@
 
 
 GLenum doubleBuffer;
+int win;
 
 static void Init(void)
 {
@@ -59,7 +60,8 @@ static void Key(unsigned char key, int x, int y)
 
     switch (key) {
       case 27:
-	exit(1);
+         glutDestroyWindow(win);
+	exit(0);
       default:
 	return;
     }
@@ -122,7 +124,8 @@ int main(int argc, char **argv)
     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
     glutInitDisplayMode(type);
 
-    if (glutCreateWindow("First Tri") == GL_FALSE) {
+    win = glutCreateWindow("First Tri");
+    if (!win) {
 	exit(1);
     }
 
diff --git a/progs/vp/Makefile b/progs/vp/Makefile
index 3349fd5342..28d63237a4 100644
--- a/progs/vp/Makefile
+++ b/progs/vp/Makefile
@@ -40,9 +40,9 @@ INCLUDES = -I. -I$(TOP)/include -I../samples
 default: $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
-	rm -f getproclist.h
+	-rm -f $(PROGS)
+	-rm -f *.o
+	-rm -f getproclist.h
 
 
 
diff --git a/progs/xdemos/.gitignore b/progs/xdemos/.gitignore
index 23e7c3ea18..868249db88 100644
--- a/progs/xdemos/.gitignore
+++ b/progs/xdemos/.gitignore
@@ -16,6 +16,7 @@ offset
 overlay
 pbdemo
 pbinfo
+sharedtex
 texture_from_pixmap
 wincopy
 xdemo
diff --git a/progs/xdemos/glthreads.c b/progs/xdemos/glthreads.c
index e9c654c649..4f87ee75d4 100644
--- a/progs/xdemos/glthreads.c
+++ b/progs/xdemos/glthreads.c
@@ -24,6 +24,7 @@
  * This program tests GLX thread safety.
  * Command line options:
  *  -p                       Open a display connection for each thread
+ *  -l                       Enable application-side locking
  *  -n <num threads>         Number of threads to create (default is 2)
  *  -display <display name>  Specify X display (default is :0.0)
  *
@@ -405,6 +406,19 @@ clean_up(void)
 }
 
 
+static void
+usage(void)
+{
+   printf("glthreads: test of GL thread safety (any key = exit)\n");
+   printf("Usage:\n");
+   printf("  glthreads [options]\n");
+   printf("Options:\n");
+   printf("   -display DISPLAYNAME  Specify display string\n");
+   printf("   -n NUMTHREADS  Number of threads to create\n");
+   printf("   -p  Use a separate display connection for each thread\n");
+   printf("   -l  Use application-side locking\n");
+}
+
 
 int
 main(int argc, char *argv[])
@@ -416,9 +430,7 @@ main(int argc, char *argv[])
    Status threadStat;
 
    if (argc == 1) {
-      printf("glthreads: test of GL thread safety (any key = exit)\n");
-      printf("Usage:\n");
-      printf("  glthreads [-display dpyName] [-n numthreads]\n");
+      usage();
    }
    else {
       int i;
@@ -442,13 +454,14 @@ main(int argc, char *argv[])
             i++;
          }
          else {
-            fprintf(stderr, "glthreads: unexpected flag: %s\n", argv[i]);
+            usage();
+            exit(1);
          }
       }
    }
    
    if (Locking)
-      printf("glthreads: Using explict locks around Xlib calls.\n");
+      printf("glthreads: Using explicit locks around Xlib calls.\n");
    else
       printf("glthreads: No explict locking.\n");