From 074dc9a023b3967ce00aa42c26a7c988423afe8a Mon Sep 17 00:00:00 2001
From: Eric Anholt <anholt@freebsd.org>
Date: Tue, 25 Apr 2006 16:47:23 +0000
Subject: [PATCH] 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                    |  9 ++++++++
 exa/exa_migration.c          | 43 ++++++++++++++++++++++++++++++++++++
 exa/exa_priv.h               |  1 +
 hw/kdrive/ephyr/ephyr_draw.c |  1 +
 4 files changed, 54 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 1d2a0fa8a..2d0473920 100644
--- a/ChangeLog
+++ b/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):
diff --git a/exa/exa_migration.c b/exa/exa_migration.c
index ef7cfd86e..8077f6802 100644
--- a/exa/exa_migration.c
+++ b/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.
      */
diff --git a/exa/exa_priv.h b/exa/exa_priv.h
index 89f8b0c9d..42c2f2d26 100644
--- a/exa/exa_priv.h
+++ b/exa/exa_priv.h
@@ -108,6 +108,7 @@ typedef struct {
     Bool			 swappedOut;
     enum ExaMigrationHeuristic	 migration;
     Bool			 hideOffscreenPixmapData;
+    Bool			 checkDirtyCorrectness;
 } ExaScreenPrivRec, *ExaScreenPrivPtr;
 
 /*
diff --git a/hw/kdrive/ephyr/ephyr_draw.c b/hw/kdrive/ephyr/ephyr_draw.c
index 0d095352f..0c1a5d0d3 100644
--- a/hw/kdrive/ephyr/ephyr_draw.c
+++ b/hw/kdrive/ephyr/ephyr_draw.c
@@ -515,4 +515,5 @@ exaDDXDriverInit(ScreenPtr pScreen)
 
     pExaScr->migration = ExaMigrationSmart;
     pExaScr->hideOffscreenPixmapData = TRUE;
+    pExaScr->checkDirtyCorrectness = TRUE;
 }