[patch] xorg-server-1.6.3-fix_random_blanking.patch

xorg-server-1.6.3-fix_random_blanking.patch (text/plain), 2.21 KB, created by Colin Macdonald on 2009-08-16 18:10:34 UTC

From db568f9eabf3450d8a023597ff007df355b13ea8 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <[e-mail]>
Date: Thu, 13 Aug 2009 06:37:00 +0000
Subject: Xext: fix up wrong conditions for negative sync transitions.

If the counter had a value higher than the trigger value for a negative
transition, the trigger value did not get set.

The correct sequence of checks is:
if (positive transition)
   if (counter value < trigger value)
      set up trigger
if (negative transition)
   if (counter value > trigger value)
      set up trigger

Red Hat Bug 501601 <https://bugzilla.redhat.com/show_bug.cgi?id=501601>

Signed-off-by: Peter Hutterer <[e-mail]>
---
diff --git a/Xext/sync.c b/Xext/sync.c
index 5f4ce56..667f8ab 100644
--- a/Xext/sync.c
+++ b/Xext/sync.c
@@ -962,28 +962,24 @@ SyncComputeBracketValues(SyncCounter *pCounter, Bool startOver)
 		pnewltval = &psci->bracket_less;
 	    }
 	}
-	else if ( (pTrigger->test_type == XSyncPositiveTransition &&
+	else if (pTrigger->test_type == XSyncNegativeTransition &&
 		   ct != XSyncCounterNeverIncreases)
-		 ||
-		 (pTrigger->test_type == XSyncNegativeTransition &&
+	{
+	    if (XSyncValueGreaterThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueGreaterThan(pTrigger->test_value, psci->bracket_less))
+	    {
+		psci->bracket_less = pTrigger->test_value;
+		pnewltval = &psci->bracket_less;
+	    }
+	}
+        else if (pTrigger->test_type == XSyncPositiveTransition &&
 		  ct != XSyncCounterNeverDecreases)
-		 )
 	{
-	    if (XSyncValueLessThan(pCounter->value, pTrigger->test_value))
+	    if (XSyncValueLessThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueLessThan(pTrigger->test_value, psci->bracket_greater))
 	    {
-		if (XSyncValueLessThan(pTrigger->test_value,
-				       psci->bracket_greater))
-		{
-		    psci->bracket_greater = pTrigger->test_value;
-		    pnewgtval = &psci->bracket_greater;
-		}
-		else
-		if (XSyncValueGreaterThan(pTrigger->test_value,
-					  psci->bracket_less))
-		{
-		    psci->bracket_less = pTrigger->test_value;
-		    pnewltval = &psci->bracket_less;
-		}
+		psci->bracket_greater = pTrigger->test_value;
+		pnewgtval = &psci->bracket_greater;
 	    }
 	}
     } /* end for each trigger */
--
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