r600g: fix broken streamout if streamout_begin caused a context flush

This fixes graphics corruption in the case where the DISCARD_RANGE flag
is used to map a buffer.

NOTE: This is a candidate for the stable branches.
(cherry picked from commit cff4c948ed2708a6eb4b090ae87443a707cbd67f)

diff --git a/src/gallium/drivers/r600/r600_hw_context.c b/src/gallium/drivers/r600/r600_hw_context.c
index 5c9c21f..af27fd9 100644 (file)
--- a/src/gallium/drivers/r600/r600_hw_context.c
+++ b/src/gallium/drivers/r600/r600_hw_context.c
@@ -1080,13 +1080,14 @@ void r600_context_streamout_begin(struct r600_context *ctx)
        unsigned *stride_in_dw = ctx->vs_shader->so.stride;
        unsigned buffer_en, i, update_flags = 0;
        uint64_t va;
+       unsigned num_cs_dw_streamout_end;
 
        buffer_en = (ctx->num_so_targets >= 1 && t[0] ? 1 : 0) |
                    (ctx->num_so_targets >= 2 && t[1] ? 2 : 0) |
                    (ctx->num_so_targets >= 3 && t[2] ? 4 : 0) |
                    (ctx->num_so_targets >= 4 && t[3] ? 8 : 0);
 
-       ctx->num_cs_dw_streamout_end =
+       num_cs_dw_streamout_end =
                12 + /* flush_vgt_streamout */
                util_bitcount(buffer_en) * 8 + /* STRMOUT_BUFFER_UPDATE */
                3 /* set_streamout_enable(0) */;
@@ -1100,7 +1101,10 @@ void r600_context_streamout_begin(struct r600_context *ctx)
                           util_bitcount(buffer_en & ctx->streamout_append_bitmask) * 8 + /* STRMOUT_BUFFER_UPDATE */
                           util_bitcount(buffer_en & ~ctx->streamout_append_bitmask) * 6 + /* STRMOUT_BUFFER_UPDATE */
                           (ctx->family > CHIP_R600 && ctx->family < CHIP_RS780 ? 2 : 0) + /* SURFACE_BASE_UPDATE */
-                          ctx->num_cs_dw_streamout_end, TRUE);
+                          num_cs_dw_streamout_end, TRUE);
+
+       /* This must be set after r600_need_cs_space. */
+       ctx->num_cs_dw_streamout_end = num_cs_dw_streamout_end;
 
        if (ctx->chip_class >= EVERGREEN) {
                evergreen_flush_vgt_streamout(ctx);