Hi,

I was getting the audio problems described here:
www.alsa-project.org/misc/vgakills.txt

It's caused by writing to a FIFO without checking if it's full or not, and
if it is full, the PCI bus locks up for long enough to damage the audio
stream to the sound card.  I've fixed it for the trident cyberblade chip.

I basically made guesses where the checks should go, as if they go before
every single BLADE_OUT(), then X wont start. It works for me, but consider
it a draft.  I called the new function BladeSync_unsafe(), because it's
based on BladeSync() but doesn't check for timeouts or other stuff.

btw, There were recent posts on the xorg mailing list about the CyberBladeXP4 
not being accelerated, is it possible the problems are related?

Laurence


--- old/xc/programs/Xserver/hw/xfree86/drivers/trident/blade_accel.c    2004-07-
30 21:30:55.000000000 +0100
+++ xc/programs/Xserver/hw/xfree86/drivers/trident/blade_accel.c        2005-05-
14 23:47:27.000000000 +0100
@@ -41,6 +41,10 @@
 #include "xaalocal.h"

 static void BladeSync(ScrnInfoPtr pScrn);
+static void BladeSync_unsafe(ScrnInfoPtr pScrn);
+
+static int busy;
+
 #if 0
 static void BladeSetupForSolidLine(ScrnInfoPtr pScrn, int color,
                                int rop, unsigned int planemask);
@@ -270,6 +274,16 @@
     }
 }

+
+static void
+BladeSync_unsafe(ScrnInfoPtr pScrn)
+{
+       TRIDENTPtr pTrident = TRIDENTPTR(pScrn);
+       BLADEBUSY(busy);
+       while (busy != 0) { BLADEBUSY(busy); };
+}
+
+
 static void
 BladeSetupForScreenToScreenCopy(ScrnInfoPtr pScrn,
                                int xdir, int ydir, int rop,
@@ -292,6 +306,7 @@
        pTrident->BltScanDirection |= 1<<5;
     }
 #endif
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2148, XAAGetCopyROP(rop));
 }

@@ -304,6 +319,7 @@

     if (pTrident->Clipping) clip = 1;

+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2144, 0xE0000000 | 1<<19 | 1<<4 | 1<<2 | pTrident-
>BltScanDirection | clip);

     if (pTrident->BltScanDirection) {
@@ -470,6 +486,7 @@
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

     REPLICATE(color);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2160, color);
     BLADE_OUT(0x2148, XAAGetCopyROP(rop));
     pTrident->BltScanDirection = 0;
@@ -487,6 +504,7 @@
 {
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2144, 0x20000000 | pTrident->BltScanDirection | 1<<19 | 1<<4 | 
2<<2 | (pTrident->Clipping ? 1:0));
     BLADE_OUT(0x2108, y<<16 | x);
     BLADE_OUT(0x210C, ((y+h-1)&0xfff)<<16 | ((x+w-1)&0xfff));
@@ -538,6 +556,7 @@
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

     pTrident->BltScanDirection = 0;
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2148, XAAGetCopyROP(rop));
     if (bg == -1) {
        pTrident->BltScanDirection |= 2<<19;
@@ -567,6 +586,7 @@
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

     if (skipleft) BladeSetClippingRectangle(pScrn,x+skipleft,y,(x+w-1),(y+h-1)
);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2144, 0xE0000000 | pTrident->BltScanDirection | 1<<4 | 
(skipleft ? 1 : 0));
     BLADE_OUT(0x2108, (y&0xfff)<<16 | (x&0xfff));
     BLADE_OUT(0x210C, ((y+h-1)&0xfff)<<16 | ((x+w-1)&0xfff));
@@ -580,13 +600,14 @@
 {
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

-    BladeSync(pScrn);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2148, XAAGetPatternROP(rop));

     if (bg == -1) {
     REPLICATE(fg);
     BLADE_OUT(0x216C, 0x80000000 | 1<<30);
     BLADE_OUT(0x216C, 0x80000000 | 1<<28 | 1<<30);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2170, patternx);
     BLADE_OUT(0x2170, patterny);
     BLADE_OUT(0x2174, fg);
@@ -598,6 +619,7 @@
     REPLICATE(bg);
     BLADE_OUT(0x216C, 0x80000000);
     BLADE_OUT(0x216C, 0x80000000 | 1<<28);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2170, patternx);
     BLADE_OUT(0x2170, patterny);
     BLADE_OUT(0x2174, fg);
@@ -623,6 +645,7 @@
     int clip = 0;

     if (pTrident->Clipping) clip = 1;
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2144, 0x20000000 | pTrident->BltScanDirection | 7<<12 | 1<<4 | 
1<<19 | 2<<2 | clip);
     BLADE_OUT(0x2108, y<<16 | x);
     BLADE_OUT(0x210C, ((y+h-1)&0xfff)<<16 | ((x+w-1)&0xfff));
@@ -677,6 +700,7 @@
 ){
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2148, XAAGetCopyROP(rop));
     pTrident->BltScanDirection = 0;
 #if 0
@@ -696,6 +720,7 @@
     TRIDENTPtr pTrident = TRIDENTPTR(pScrn);

     if (skipleft) BladeSetClippingRectangle(pScrn,x+skipleft,y,(x+w-1),(y+h-1)
);
+    BladeSync_unsafe(pScrn);
     BLADE_OUT(0x2144, 0xE0000000 | 1<<19 | 1<<4 | pTrident->BltScanDirection | 
(skipleft ? 1 : 0));
     BLADE_OUT(0x2108, y<<16 | (x&0xfff));
     BLADE_OUT(0x210C, ((y+h-1)&0xfff)<<16 | ((x+w-1)&0xfff));