Mesa (master): ilo: 3DSTATE_INDEX_BUFFER may be wrongly skipped

[Chia-I Wu]

Module: Mesa
Branch: master
Commit: b2f79a3823bd5fca3f3080351f87b41e2396c8f6
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b2f79a3823bd5fca3f3080351f87b41e2396c8f6

Author: Chia-I Wu <olvaffe at gmail.com>
Date:   Sat Aug 10 00:48:28 2013 +0800

ilo: 3DSTATE_INDEX_BUFFER may be wrongly skipped

In finalize_index_buffer(), when the current index buffer was destroyed due to
u_upload_data(), it may happen that the new index buffer is at the same
address as the old one.  Comparing the pointers to the two buffers could fail
to work, and 3DSTATE_INDEX_BUFFER would be incorrectly skipped.

Holding a reference to the current index buffer before calling u_upload_data()
should fix the problem.

---

 src/gallium/drivers/ilo/ilo_state.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/src/gallium/drivers/ilo/ilo_state.c b/src/gallium/drivers/ilo/ilo_state.c
index 86470a7..ce6930c 100644
--- a/src/gallium/drivers/ilo/ilo_state.c
+++ b/src/gallium/drivers/ilo/ilo_state.c
@@ -128,13 +128,15 @@ finalize_constant_buffers(struct ilo_context *ilo)
 static void
 finalize_index_buffer(struct ilo_context *ilo)
 {
-   const struct pipe_resource *current_hw_res = ilo->ib.hw_resource;
    const bool need_upload = (ilo->draw->indexed &&
          (ilo->ib.user_buffer || ilo->ib.offset % ilo->ib.index_size));
+   struct pipe_resource *current_hw_res = NULL;
 
    if (!(ilo->dirty & ILO_DIRTY_IB) && !need_upload)
       return;
 
+   pipe_resource_reference(&current_hw_res, ilo->ib.hw_resource);
+
    if (need_upload) {
       const unsigned offset = ilo->ib.index_size * ilo->draw->start;
       const unsigned size = ilo->ib.index_size * ilo->draw->count;
@@ -175,6 +177,8 @@ finalize_index_buffer(struct ilo_context *ilo)
       ilo->dirty &= ~ILO_DIRTY_IB;
    else
       ilo->ib.hw_index_size = ilo->ib.index_size;
+
+   pipe_resource_reference(&current_hw_res, NULL);
 }
 
 /**