[Dri-devel] Re: Problem with a matrox G400

[Alessio <al...@it...>]

Hello, 
   sorry for the missing references to the previous postings
   but I read them on the site.
   Ok, I experienced the same problem of Failure in texture upload.o
   My system has a G200 AGP with 8 MB.
   I think this 8 mb of ram are the clue of both the texture problem
   and (someway related) of the mga_get_buffer_ioctl() problem.
   When i saw that error... and that NIL I decided to do
   a lil surfing between the amazon of the X source code.
   (X 4.1.0)
   [ i will give you a looong answer so get your
     preferred wine and sit comfortably ]
   The error is reported from the mgatexmem.c file within the
   libGL DRI extensions:

         if (mmesa->TexObjList[heap].prev ==
             &(mmesa->TexObjList[heap]))
         {
            fprintf(stderr, "Failed to upload texture, sz %d\n",
t->totalSize);
            mmDumpMemInfo( mmesa->texHeap[heap] );
            return -1;
         }

  Look at the lines around... it tries to do this: 
          t->MemBlock = mmAllocMem( mmesa->texHeap[heap],
                                   t->totalSize,
                                   6, 0 );

   Now, from the error we know mmesa->texHeap[heap] is NIL and heap is 0
   mmAllocMem doesn't allocate memory if the originating region (the 1st
   parameter) is NULL. This is the problem: t->memBlock will be ALWAYS
   NULL.
   Looking at my XFree log i noticed this (and please confirm me it):
   MGA(0): Reserved 0 kb for textures at offset .....
   
   Let's take a look to the AccelInit() function into the mga_storm.c file
   
       pMGADRIServer->textureSize = pMga->FbMapSize - 5 * bufferSize;

   This variable is the size (in bytes) allocated for the textures..
   bufferSize (defined as (pScrn->virtualY * bpp/8) and then aligned)
   on my system is ~ 2 mb.
   FbMapSize is the size allowed for all our video buffers memory
   ( i think the RAM on the card ) in fact it's 8 MB on my system.
   A few math: 8 - (5*2) is less than 0. Oh no!
   OK... let's continue reading this: 
              if(pMGADRIServer->textureSize < 512*1024)
        {
                pMGADRIServer->textureSize = 0;
                pMGADRIServer->textureOffset = 0;
        }

   The comment just above says : 'make enough room for two 256x256x32bpp
   textures'. This is strange... i think it should be..
        pMGADRIServer->textureSize= 512*1024;
   I recompiled the driver and restarted X.
   Hm... first change:
       (EE) MGA(0): Memory manager initialization to (0,0) (1280,1023) failed
   This is quite not good...but I really don't know WHY it doesn't work.
   Now, tuxracer works perfectly... and Quake 3 seems to work in a 
   1024x768 fashion without problems.. OH YES!
   Tuxracer works for about half an hour... and then I decided 'it works'
   Quake 3... works.. but I now started to exprience the second problem
   (mga_get_buffer_ioctl: err=-16, hardware busy)
   This is quite harded to solve... because we are talking about
   the DRM layer and DMA transfers... now, i think it's not because
   I changed that senseless zero... and I am about to 
   update my bios just after pressing my esc-:wq y sequence.
   Byeeee
			Alessio