commit c8ab32fa8ee16e0b924e28f3299c7c3306551c24
Author: Kenneth Graunke <kenneth@whitecape.org>
Date:   Wed Apr 15 03:04:33 2015 -0700

    GAH.  The blitter now requires cacheline aligned addresses
    
    I suspect the unaligned part just doesn't get copied, leading to bunk
    data in your destination...

diff --git a/src/mesa/drivers/dri/i965/intel_blit.c b/src/mesa/drivers/dri/i965/intel_blit.c
index 9500bd7..1d39543 100644
--- a/src/mesa/drivers/dri/i965/intel_blit.c
+++ b/src/mesa/drivers/dri/i965/intel_blit.c
@@ -524,6 +524,7 @@ intel_emit_linear_blit(struct brw_context *brw,
 {
    struct gl_context *ctx = &brw->ctx;
    GLuint pitch, height;
+   int16_t src_x, dst_x;
    bool ok;
 
    /* The pitch given to the GPU must be DWORD aligned, and
@@ -532,11 +533,19 @@ intel_emit_linear_blit(struct brw_context *brw,
     */
    pitch = ROUND_DOWN_TO(MIN2(size, (1 << 15) - 1), 4);
    height = (pitch == 0) ? 1 : size / pitch;
+   if ((src_offset % 64) != 0) {
+      fprintf(stderr, "BAD SRC OFFSET #1: %d (%d)\n", src_offset, src_offset % 64);
+   }
+   if ((dst_offset % 64) != 0) {
+      fprintf(stderr, "BAD DST OFFSET #1: %d (%d)\n", dst_offset, dst_offset % 64);
+   }
+   src_x = src_offset % 64;
+   dst_x = dst_offset % 64;
    ok = intelEmitCopyBlit(brw, 1,
-			  pitch, src_bo, src_offset, I915_TILING_NONE,
-			  pitch, dst_bo, dst_offset, I915_TILING_NONE,
-			  0, 0, /* src x/y */
-			  0, 0, /* dst x/y */
+			  pitch, src_bo, src_offset - src_x, I915_TILING_NONE,
+			  pitch, dst_bo, dst_offset - dst_x, I915_TILING_NONE,
+			  src_x, 0, /* src x/y */
+			  dst_x, 0, /* dst x/y */
 			  pitch, height, /* w, h */
 			  GL_COPY);
    if (!ok)
@@ -544,15 +553,25 @@ intel_emit_linear_blit(struct brw_context *brw,
 
    src_offset += pitch * height;
    dst_offset += pitch * height;
+   src_x = src_offset % 64;
+   dst_x = dst_offset % 64;
    size -= pitch * height;
    assert (size < (1 << 15));
    pitch = ALIGN(size, 4);
+
    if (size != 0) {
+      if ((src_offset % 64) != 0) {
+         fprintf(stderr, "BAD SRC OFFSET #2: %d (%d)\n", src_offset, src_offset % 64);
+      }
+      if ((dst_offset % 64) != 0) {
+         fprintf(stderr, "BAD DST OFFSET #2: %d (%d)\n", dst_offset, dst_offset % 64);
+      }
+
       ok = intelEmitCopyBlit(brw, 1,
-			     pitch, src_bo, src_offset, I915_TILING_NONE,
-			     pitch, dst_bo, dst_offset, I915_TILING_NONE,
-			     0, 0, /* src x/y */
-			     0, 0, /* dst x/y */
+			     pitch, src_bo, src_offset - src_x, I915_TILING_NONE,
+			     pitch, dst_bo, dst_offset - dst_x, I915_TILING_NONE,
+			     src_x, 0, /* src x/y */
+			     dst_x, 0, /* dst x/y */
 			     size, 1, /* w, h */
 			     GL_COPY);
       if (!ok)