Bug 105807

Created attachment 138419 [details]
Ingame Image

Works correctly in radeonsi doesn't work in i965. Probably requires more restrictions when 3.1 compant not available. Moving to i965 where it's less likely to get forgotten about.

Ok, it seems the problem is due to a mismatch in OpenGL version vs GLSL version. After the bisected commit i965 started reporting:

OpenGL version string: 3.0 Mesa 18.1.0-devel (git-7fe586f6fb)
OpenGL shading language version string: 1.40

Rather than:

OpenGL version string: 3.0 Mesa 18.1.0-devel (git-7fe586f6fb)
OpenGL shading language version string: 1.30

I'll see if I can come up with a patch.

Thanks for the bug report.

Fix sent to list:

https://patchwork.freedesktop.org/patch/216148/

Hi Timothy, 
I think you're on the right track but radeonsi git also (still) doesnt work as of just now.

I get

glXCreateContextAttribsARB(dpy = 0x45623f0, config = 0x46f4a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 5, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = 0x4723d10

from the game. It shows the bug.
I dont know how to spot the GLSL version, any pointers?

If I do force the GL version to something like 3.0, 3.1 or 3.1COMPAT or
force MESA_GLSL_VERSION_OVERRIDE=130
I get this 

1187 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 5, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1189 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 4, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1191 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 3, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1193 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 2, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1195 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 1, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1197 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 4, GLX_CONTEXT_MINOR_VERSION_ARB, 0, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1199 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 3, GLX_CONTEXT_MINOR_VERSION_ARB, 3, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1201 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 3, GLX_CONTEXT_MINOR_VERSION_ARB, 2, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = NULL
1203 glXCreateContextAttribsARB(dpy = 0x52213f0, config = 0x53b3a70, share_context = NULL, direct = True, attrib_list = {GLX_CONTEXT_MAJOR_VERSION_ARB, 3, GLX_CONTEXT_MINOR_VERSION_ARB, 1, GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB, GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, GLX_NO_RESET_NOTIFICATION_ARB, 0}) = 0x554b1f0

(forcing FC seems to screw up the loader). And then the game works.

I've uploaded traces
https://github.com/bendat78/mymesa/tree/mymesa2/testresults/dow2/xz

Just to confirm with Ben, this very definitely affects radeonsi not just i965. Forcing MESA_GLSL_VERSION_OVERRIDE=130 resolves issue so perhaps a game issue with GLSL 1.4?

These are from shaderdumps (good thing I have the sha naming in place otherwise these would have been overwritten ;)

When GLSL is not forced

[require]
GLSL >= 0.00 // this is generated by OpenGL so maybe something is going on there

[fragment shader]
#version 140
#extension GL_ARB_explicit_attrib_location : enable

When forcing GLSL 1.3

[require]
GLSL >= 1.30

[vertex shader]
#version 130
#extension GL_ARB_explicit_attrib_location : enable

(In reply to Alan Swanson from comment #7)
> Just to confirm with Ben, this very definitely affects radeonsi not just
> i965. Forcing MESA_GLSL_VERSION_OVERRIDE=130 resolves issue so perhaps a
> game issue with GLSL 1.4?

What version of Mesa are you guys testing with? Are you testing with git master?

(In reply to Timothy Arceri from comment #9)
> (In reply to Alan Swanson from comment #7)
> > Just to confirm with Ben, this very definitely affects radeonsi not just
> > i965. Forcing MESA_GLSL_VERSION_OVERRIDE=130 resolves issue so perhaps a
> > game issue with GLSL 1.4?
> 
> What version of Mesa are you guys testing with? Are you testing with git
> master?

Nevermind this was my mistake I was testing with 18.0 on radeonsi which I thought had the enable OpenGL 3.1 patch but seem it doesn't. I've pushed my patch so this issue should now be fixed in drivers other than radeonsi.

I think this function is the problem:

/**
 * Return the string for a glGetString(GL_SHADING_LANGUAGE_VERSION) query.
 */
static const GLubyte *
shading_language_version(struct gl_context *ctx)
{
   switch (ctx->API) {
   case API_OPENGL_COMPAT:
   case API_OPENGL_CORE:
      switch (ctx->Const.GLSLVersion) {
      case 120:
         return (const GLubyte *) "1.20";
      case 130:
         return (const GLubyte *) "1.30";
      case 140:
         return (const GLubyte *) "1.40";
      case 150:
         return (const GLubyte *) "1.50";
      case 330:
         return (const GLubyte *) "3.30";
      case 400:
         return (const GLubyte *) "4.00";
      case 410:
         return (const GLubyte *) "4.10";
      case 420:
         return (const GLubyte *) "4.20";
      case 430:
         return (const GLubyte *) "4.30";
      case 440:
         return (const GLubyte *) "4.40";
      case 450:
         return (const GLubyte *) "4.50";
      case 460:
         return (const GLubyte *) "4.60";
      default:
         _mesa_problem(ctx,
                       "Invalid GLSL version in shading_language_version()");
         return (const GLubyte *) 0;
      }
      break;

   case API_OPENGLES2:
      switch (ctx->Version) {
      case 20:
         return (const GLubyte *) "OpenGL ES GLSL ES 1.0.16";
      case 30:
         return (const GLubyte *) "OpenGL ES GLSL ES 3.00";
      case 31:
         return (const GLubyte *) "OpenGL ES GLSL ES 3.10";
      case 32:
         return (const GLubyte *) "OpenGL ES GLSL ES 3.20";
      default:
         _mesa_problem(ctx,
                       "Invalid OpenGL ES version in shading_language_version()");
         return (const GLubyte *) 0;
      }
   case API_OPENGLES:
      /* fall-through */

   default:
      _mesa_problem(ctx, "Unexpected API value in shading_language_version()");
      return (const GLubyte *) 0;
   }
}

OpenGL core spec 4.5 page 4 specifies:

"The core profile of OpenGL 4.5 is also guaranteed to support all previous ver-
sions of the OpenGL Shading Language back to version  1.40. In some implemen-
tations the core profile may also support earlier versions of the OpenGL Shading
Language, and may support compatibility profile versions of the OpenGL Shading
Language for versions 1.40 and earlier. In this case, errors will be generated when
using language features such as compatibility profile built-ins not supported by the
core profile API.  The #version strings for all supported versions of the OpenGL
Shading Language may be queried as described in section 22.2."

But I think the above version returns 0 in cases where you request a glsl version that is lower and not a list of supported glsl versions like the function below:

from mesa/main/version.c: (the one above is getstring.c)


int
_mesa_get_shading_language_version(const struct gl_context *ctx,
                                   int index,
                                   char **versionOut)
{
   int n = 0;

#define GLSL_VERSION(S) \
   if (n++ == index) \
      *versionOut = S

   /* GLSL core */
   if (ctx->Const.GLSLVersion >= 460)
      GLSL_VERSION("460");
   if (ctx->Const.GLSLVersion >= 450)
      GLSL_VERSION("450");
   if (ctx->Const.GLSLVersion >= 440)
      GLSL_VERSION("440");
   if (ctx->Const.GLSLVersion >= 430)
      GLSL_VERSION("430");
   if (ctx->Const.GLSLVersion >= 420)
      GLSL_VERSION("420");
   if (ctx->Const.GLSLVersion >= 410)
      GLSL_VERSION("410");
   if (ctx->Const.GLSLVersion >= 400)
      GLSL_VERSION("400");
   if (ctx->Const.GLSLVersion >= 330)
      GLSL_VERSION("330");
   if (ctx->Const.GLSLVersion >= 150)
      GLSL_VERSION("150");
   if (ctx->Const.GLSLVersion >= 140)
      GLSL_VERSION("140");
   if (ctx->Const.GLSLVersion >= 130)
      GLSL_VERSION("130");
   if (ctx->Const.GLSLVersion >= 120)
      GLSL_VERSION("120");
   /* The GL spec says to return the empty string for GLSL 1.10 */
   if (ctx->Const.GLSLVersion >= 110)
      GLSL_VERSION("");

   /* GLSL es */
   if ((ctx->API == API_OPENGLES2 && ctx->Version >= 32) ||
        ctx->Extensions.ARB_ES3_2_compatibility)
      GLSL_VERSION("320 es");
   if (_mesa_is_gles31(ctx) || ctx->Extensions.ARB_ES3_1_compatibility)
      GLSL_VERSION("310 es");
   if (_mesa_is_gles3(ctx) || ctx->Extensions.ARB_ES3_compatibility)
      GLSL_VERSION("300 es");
   if (ctx->API == API_OPENGLES2 || ctx->Extensions.ARB_ES2_compatibility)
      GLSL_VERSION("100");

#undef GLSL_VERSION

   return n;
}

That would explain why a program gets a zero in return when requesting a shader language lower than the one hardcoded in comment 11. Which is exactly what happen in comment 8.

Or at least that seems reasonable doesnt it?

I'm probably too tired, but this should work I think except it doesnt.


// Little test program to dump supported shader versions

// compiled like this
// gcc test.c -I/usr/include/GL/ -L/usr/lib/x86_64-linux-gnu -lglut -lGLU -lGL -lGLEW -o test

#include "glew.h"
#include "glut.h"
#include <GL/glcorearb.h>
#include <stdio.h>

int main(int argc, char **argv)
{
    glutInit(&argc, argv);
    glutCreateWindow("GLUT");
    glewInit();

    printf("OpenGL version supported by this platform (%s): \n",
           glGetString(GL_VERSION));

    int num_glsls = 0;
    glGetIntegerv(GL_NUM_SHADING_LANGUAGE_VERSIONS, &num_glsls); 
// supposed to be at least 3 according to page 617 of the OpenGL 4.5 core spec
// currently seems to be 0
    printf("GLSL versions supported by this platform: %d", num_glsls);

// this doesnt do anything even though it should
    for (int i = 0; i++; i < num_glsls) {
       printf("OpenGLSL versions supported by this platform (%s): \n",
              glGetStringi(GL_SHADING_LANGUAGE_VERSION, 0));
    }
}

Ok so I found the problem. We didn't support compat shaders on GLSL 1.40 only on GLSL versions higher and lower.

I think the Version == 0 might be a separate issue as per comment 15 and it would be great if you could create a piglit test for that. I'll need to write a piglit test for this GLSL 1.40 compat shaders bug too.

Fix:
https://patchwork.freedesktop.org/patch/216621/

Thanks again for the report and for bisecting.

Fixed by:

commit c7e3d31b0b5f22299a6bd72655502ce8427b40bf
Author: Timothy Arceri <tarceri@itsqueeze.com>
Date:   Thu Apr 12 09:23:02 2018 +1000

    glsl: fix compat shaders in GLSL 1.40
    
    The compatibility and core tokens were not added until GLSL 1.50,
    for GLSL 1.40 just assume all shaders built with a compat profile
    are compat shaders.
    
    Fixes rendering issues in Dawn of War II on radeonsi which has
    enabled OpenGL 3.1 compat support.
    
    Fixes: a0c8b49284ef "mesa: enable OpenGL 3.1 with ARB_compatibility"
    
    Reviewed-by: Marek Olšák <marek.olsak@amd.com>
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105807

Just confirmed that it works now.

Thanks!

Maybe this should be in stable too?

(In reply to ben@besd.de from comment #18)
> Just confirmed that it works now.
> 
> Thanks!
> 
> Maybe this should be in stable too?

Fixes: a0c8b49284ef "mesa: enable OpenGL 3.1 with ARB_compatibility"

Means it will automatically get picked up by the stable scripts for inclusion into any stable release that contains that commit.