r600g/compute: solve a bug introduced by 2e01b8b440c1402c88a2755d89f40292e1f36ce5

That commit made possible that the items could be one just
after the other when their size was a multiple of ITEM_ALIGNMENT.
But compute_memory_prealloc_chunk still looked to leave a gap
between items. Resulting in that we got an infinite loop when
trying to add an item which would left no space between itself and
the next item.

Fixes piglit test: cl-custom-r600-create-release-buffer-bug
And the test for alignment I have just sent:
http://lists.freedesktop.org/archives/piglit/2014-June/011135.html

Sorry about this.

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

diff --git a/src/gallium/drivers/r600/compute_memory_pool.c b/src/gallium/drivers/r600/compute_memory_pool.c
index 2050f289475480ecbcc63734176f267ba7aa595e..ec8c470fc65c1f8241c54ee6a91c4e17c6aaed07 100644 (file)
--- a/src/gallium/drivers/r600/compute_memory_pool.c
+++ b/src/gallium/drivers/r600/compute_memory_pool.c
@@ -110,7 +110,7 @@ int64_t compute_memory_prealloc_chunk(
 
        for (item = pool->item_list; item; item = item->next) {
                if (item->start_in_dw > -1) {
-                       if (item->start_in_dw-last_end > size_in_dw) {
+                       if (last_end + size_in_dw <= item->start_in_dw) {
                                return last_end;
                        }