Add an option to verify at the point of migration that pixmaps which aren't

marked dirty are in fact not dirty. This will hopefully help catch
    issues like the previous commit. Leave it on in fakexa.

ChangeLog

@@ -1,3 +1,12 @@
+2006-04-25  Eric Anholt  <anholt@FreeBSD.org>
+
+	* exa/exa_migration.c: (exaAssertNotDirty), (exaDoMigration):
+	* exa/exa_priv.h:
+	* hw/kdrive/ephyr/ephyr_draw.c: (exaDDXDriverInit):
+	Add an option to verify at the point of migration that pixmaps which
+	aren't marked dirty are in fact not dirty.  This will hopefully help
+	catch issues like the previous commit.  Leave it on in fakexa.
+
 2006-04-25  Eric Anholt  <anholt@FreeBSD.org>
 
 	* exa/exa_accel.c: (exaPutImage):

exa/exa_migration.c

@@ -406,6 +406,36 @@ exaMigrateTowardSys (PixmapPtr pPixmap)
 	exaMoveOutPixmap (pPixmap);
 }
 
+/**
+ * If the pixmap has both a framebuffer and system memory copy, this function
+ * asserts that both of them are the same.
+ */
+static void
+exaAssertNotDirty (PixmapPtr pPixmap)
+{
+    ExaPixmapPriv (pPixmap);
+    CARD8 *dst, *src;
+    int dst_pitch, src_pitch, data_row_bytes, y;
+
+    if (pExaPixmap == NULL || pExaPixmap->fb_ptr == NULL)
+	return;
+
+    dst = pExaPixmap->sys_ptr;
+    dst_pitch = pExaPixmap->sys_pitch;
+    src = pExaPixmap->fb_ptr;
+    src_pitch = pExaPixmap->fb_pitch;
+    data_row_bytes = pPixmap->drawable.width *
+		     pPixmap->drawable.bitsPerPixel / 8;
+
+    exaPrepareAccess(&pPixmap->drawable, EXA_PREPARE_SRC);
+    for (y = 0; y < pPixmap->drawable.height; y++) {
+	if (memcmp(dst, src, data_row_bytes) != 0) {
+	     abort();
+	}
+    }
+    exaFinishAccess(&pPixmap->drawable, EXA_PREPARE_SRC);
+}
+
 /**
  * Performs migration of the pixmaps according to the operation information
  * provided in pixmaps and can_accel and the migration scheme chosen in the
@@ -418,6 +448,19 @@ exaDoMigration (ExaMigrationPtr pixmaps, int npixmaps, Bool can_accel)
     ExaScreenPriv(pScreen);
     int i, j;
 
+    /* If this debugging flag is set, check each pixmap for whether it is marked
+     * as clean, and if so, actually check if that's the case.  This should help
+     * catch issues with failing to mark a drawable as dirty.  While it will
+     * catch them late (after the operation happened), it at least explains what
+     * went wrong, and instrumenting the code to find what operation happened
+     * to the pixmap last shouldn't be hard.
+     */
+    if (pExaScr->checkDirtyCorrectness) {
+	for (i = 0; i < npixmaps; i++) {
+	    if (!exaPixmapIsDirty (pixmaps[i].pPix))
+		exaAssertNotDirty (pixmaps[i].pPix);
+	}
+    }
     /* If anything is pinned in system memory, we won't be able to
      * accelerate.
      */

exa/exa_priv.h

@@ -108,6 +108,7 @@ typedef struct {
     Bool			 swappedOut;
     enum ExaMigrationHeuristic	 migration;
     Bool			 hideOffscreenPixmapData;
+    Bool			 checkDirtyCorrectness;
 } ExaScreenPrivRec, *ExaScreenPrivPtr;
 
 /*

hw/kdrive/ephyr/ephyr_draw.c

@@ -515,4 +515,5 @@ exaDDXDriverInit(ScreenPtr pScreen)
 
     pExaScr->migration = ExaMigrationSmart;
     pExaScr->hideOffscreenPixmapData = TRUE;
+    pExaScr->checkDirtyCorrectness = TRUE;
 }