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updated DMA acc to use the full DMA buffersize instead of just one quarter.

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Also improved forced freespace limit setting in this buffer, now finally completely preventing engine crashes it seems.
Engine speed went up again due to larger DMA buffer.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@11089 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Rudolf Cornelissen 2005-01-27 10:23:52 +00:00
parent 739532577c
commit d4d5ee8bbb
1 changed files with 29 additions and 16 deletions
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45
src/add-ons/accelerants/nvidia/engine/nv_acc_dma.c
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@ -578,6 +578,8 @@ status_t nv_acc_init_dma()
/* all cards: */
/* setup clipping: rect size is 32768 x 32768, probably max. setting */
/* note:
* can also be done via the NV_IMAGE_BLACK_RECTANGLE engine command. */
ACCW(ABS_UCLP_XMIN, 0x00000000);
ACCW(ABS_UCLP_YMIN, 0x00000000);
ACCW(ABS_UCLP_XMAX, 0x00007fff);
@ -700,8 +702,7 @@ status_t nv_acc_init_dma()
* one word is reserved at the end of the DMA buffer to be able to instruct the
* engine to do a buffer wrap-around!
* (DMA opcode 'noninc method': issue word $20000000.) */
//testing:
si->engine.dma.max = 2048 - 1;//8192 - 1;
si->engine.dma.max = 8192 - 1;
/* note the current free space we have left in the DMA buffer */
si->engine.dma.free = si->engine.dma.max - si->engine.dma.current;
@ -883,15 +884,21 @@ static status_t nv_acc_fifofree_dma(uint16 cmd_size)
/* note the updated current free space we have in the DMA buffer */
si->engine.dma.free = dmaget - si->engine.dma.current;
/* mind this pittfall (? there might be another reason):
* as the engine is DMA triggered for fetching chunks every 128 bytes,
* we may not touch that much at the end of our free space!
* (confirmed NV11 and NV43 when their buffer is full for a longer
* period of time, tested with BeRoMeter 1.2.6.) */
if (si->engine.dma.free < 32)
/* mind this pittfall:
* Leave some room between where the engine is fetching and where we
* put new commands. Otherwise the engine will crash on heavy loads.
* A crash can be forced best in 640x480 resolution with BeRoMeter 1.2.6.
* (confirmed on NV11 and NV43 with less than 64 words forced freespace.)
* Note:
* The engine is DMA triggered for fetching chunks every 128 bytes,
* maybe this is the reason for this behaviour.
* Note also:
* it looks like the space that needs to be kept free is coupled
* with the size of the DMA buffer. */
if (si->engine.dma.free < 64)
si->engine.dma.free = 0;
else
si->engine.dma.free -= 32;
si->engine.dma.free -= 64;
}
}
else
@ -901,15 +908,21 @@ static status_t nv_acc_fifofree_dma(uint16 cmd_size)
/* note the updated current free space we have in the DMA buffer */
si->engine.dma.free = dmaget - si->engine.dma.current;
/* mind this pittfall (? there might be another reason):
* as the engine is DMA triggered for fetching chunks every 128 bytes,
* we may not touch that much at the end of our free space!
* (confirmed NV11 and NV43 when their buffer is full for a longer period
* of time, tested with BeRoMeter 1.2.6.) */
if (si->engine.dma.free < 32)
/* mind this pittfall:
* Leave some room between where the engine is fetching and where we
* put new commands. Otherwise the engine will crash on heavy loads.
* A crash can be forced best in 640x480 resolution with BeRoMeter 1.2.6.
* (confirmed on NV11 and NV43 with less than 64 words forced freespace.)
* Note:
* The engine is DMA triggered for fetching chunks every 128 bytes,
* maybe this is the reason for this behaviour.
* Note also:
* it looks like the space that needs to be kept free is coupled
* with the size of the DMA buffer. */
if (si->engine.dma.free < 64)
si->engine.dma.free = 0;
else
si->engine.dma.free -= 32;
si->engine.dma.free -= 64;
}
}