Mesa (master): svga: change error handling convention for svga_set_stream_output()

[Brian Paul]

Module: Mesa
Branch: master
Commit: 4f3974d7586070fe72a9ef09d3df3f24b4a49f43
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4f3974d7586070fe72a9ef09d3df3f24b4a49f43

Author: Brian Paul <brianp at vmware.com>
Date:   Thu Jun 22 14:45:07 2017 -0600

svga: change error handling convention for svga_set_stream_output()

In general, the functions which emit commands to the command buffer check
for failure and return a PIPE_ERROR_x code.  It's up to the caller to
flush the buffer and retry the command.

But svga_set_stream_output() did its own flushing and the callers never
checked the return value (though, it would always be PIPE_OK) in practice.

This patch changes svga_set_stream_output() so that it does not call
svga_context_flush() when the buffer is full.  And we update the callers
to check the return value as we do for other functions, like
svga_set_shader().

No Piglit regressions.  Also tested w/ Nature demo.

Reviewed-by: Charmaine Lee <charmainel at vmware.com>

---

 src/gallium/drivers/svga/svga_pipe_streamout.c | 13 +++++--------
 src/gallium/drivers/svga/svga_state_gs.c       | 10 ++++++++--
 src/gallium/drivers/svga/svga_state_vs.c       |  7 +++++--
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/gallium/drivers/svga/svga_pipe_streamout.c b/src/gallium/drivers/svga/svga_pipe_streamout.c
index 4add087888..3f30e648c0 100644
--- a/src/gallium/drivers/svga/svga_pipe_streamout.c
+++ b/src/gallium/drivers/svga/svga_pipe_streamout.c
@@ -157,7 +157,6 @@ enum pipe_error
 svga_set_stream_output(struct svga_context *svga,
                        struct svga_stream_output *streamout)
 {
-   enum pipe_error ret = PIPE_OK;
    unsigned id = streamout ? streamout->id : SVGA3D_INVALID_ID;
 
    if (!svga_have_vgpu10(svga)) {
@@ -168,17 +167,15 @@ svga_set_stream_output(struct svga_context *svga,
             streamout, id);
 
    if (svga->current_so != streamout) {
-      /* Save current SO state */
-      svga->current_so = streamout;
-
-      ret = SVGA3D_vgpu10_SetStreamOutput(svga->swc, id);
+      enum pipe_error ret = SVGA3D_vgpu10_SetStreamOutput(svga->swc, id);
       if (ret != PIPE_OK) {
-         svga_context_flush(svga, NULL);
-         ret = SVGA3D_vgpu10_SetStreamOutput(svga->swc, id);
+         return ret;
       }
+
+      svga->current_so = streamout;
    }
 
-   return ret;
+   return PIPE_OK;
 }
 
 void
diff --git a/src/gallium/drivers/svga/svga_state_gs.c b/src/gallium/drivers/svga/svga_state_gs.c
index 217463882f..19f0887d2b 100644
--- a/src/gallium/drivers/svga/svga_state_gs.c
+++ b/src/gallium/drivers/svga/svga_state_gs.c
@@ -201,11 +201,17 @@ emit_hw_gs(struct svga_context *svga, unsigned dirty)
     * it instead of the one from the vertex shader.
     */
    if (svga_have_gs_streamout(svga)) {
-      svga_set_stream_output(svga, gs->base.stream_output);
+      ret = svga_set_stream_output(svga, gs->base.stream_output);
+      if (ret != PIPE_OK) {
+         goto done;
+      }
    }
    else if (!svga_have_vs_streamout(svga)) {
       /* turn off stream out */
-      svga_set_stream_output(svga, NULL);
+      ret = svga_set_stream_output(svga, NULL);
+      if (ret != PIPE_OK) {
+         goto done;
+      }
    }
 
    /* SVGA_NEW_NEED_SWTNL */
diff --git a/src/gallium/drivers/svga/svga_state_vs.c b/src/gallium/drivers/svga/svga_state_vs.c
index 325ef3ebad..a0ab868cbb 100644
--- a/src/gallium/drivers/svga/svga_state_vs.c
+++ b/src/gallium/drivers/svga/svga_state_vs.c
@@ -353,11 +353,14 @@ emit_hw_vs(struct svga_context *svga, unsigned dirty)
       /* No GS stream out */
       if (svga_have_vs_streamout(svga)) {
          /* Set VS stream out */
-         svga_set_stream_output(svga, vs->base.stream_output);
+         ret = svga_set_stream_output(svga, vs->base.stream_output);
       }
       else {
          /* turn off stream out */
-         svga_set_stream_output(svga, NULL);
+         ret = svga_set_stream_output(svga, NULL);
+      }
+      if (ret != PIPE_OK) {
+         goto done;
       }
    }