Add a test to try to fill the ring.

Did this while trying to debug the Ubuntu DRI1+compiz issue.  Didn't succeed
in filling the ring.

.gitignore

@@ -40,6 +40,7 @@ tests/gem_flink
 tests/gem_mmap
 tests/gem_pread_after_blit
 tests/gem_readwrite
+tests/gem_ringfill
 tests/gem_tiled_blits
 tests/gem_tiled_pread
 tools/intel_gpu_dump

tests/Makefile.am

@@ -4,6 +4,7 @@ TESTS = getversion \
 	gem_basic \
 	gem_flink \
 	gem_readwrite \
+	gem_ringfill \
 	gem_mmap \
 	gem_pread_after_blit \
 	gem_tiled_pread \

tests/gem_ringfill.c

@@ -0,0 +1,97 @@
+/*
+ * Copyright © 2009 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *
+ */
+
+/** @file gem_ringfill.c
+ *
+ * This is a test of doing many tiny batchbuffer operations, in the hope of
+ * catching failure to manage the ring properly near full.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include "drm.h"
+#include "i915_drm.h"
+#include "drmtest.h"
+#include "intel_bufmgr.h"
+#include "intel_batchbuffer.h"
+#include "intel_gpu_tools.h"
+
+static drm_intel_bufmgr *bufmgr;
+struct intel_batchbuffer *batch;
+static const int width = 512, height = 512;
+static const int size = 1024 * 1024;
+
+int main(int argc, char **argv)
+{
+	int fd;
+	int i;
+	drm_intel_bo *src_bo, *dst_bo;
+
+	fd = drm_open_any();
+	intel_get_drm_devid(fd);
+
+	bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
+	drm_intel_bufmgr_gem_enable_reuse(bufmgr);
+	batch = intel_batchbuffer_alloc(bufmgr);
+
+	src_bo = drm_intel_bo_alloc(bufmgr, "src bo", size, 4096);
+	dst_bo = drm_intel_bo_alloc(bufmgr, "src bo", size, 4096);
+
+	/* The ring we've been using is 128k, and each rendering op
+	 * will use at least 8 dwords:
+	 *
+	 * BATCH_START
+	 * BATCH_START offset
+	 * MI_FLUSH
+	 * STORE_DATA_INDEX
+	 * STORE_DATA_INDEX offset
+	 * STORE_DATA_INDEX value
+	 * MI_USER_INTERRUPT
+	 * (padding)
+	 *
+	 * So iterate just a little more than that -- if we don't fill the ring
+	 * doing this, we aren't likely to with this test.
+	 */
+	for (i = 0; i < 128 * 1024 / (8 * 4) * 1.25; i++) {
+		intel_copy_bo(batch, dst_bo, src_bo, width, height);
+		intel_batchbuffer_flush(batch);
+	}
+
+	intel_batchbuffer_free(batch);
+	drm_intel_bufmgr_destroy(bufmgr);
+
+	close(fd);
+
+	return 0;
+}