[Mesa-dev] [PATCH] i965/batch: don't ignore the 'brw_new_batch' call for a 'new batch'

[asimiklit.work at gmail.com]

From: Andrii Simiklit <andrii.simiklit at globallogic.com>

If we restore the 'new batch' using 'intel_batchbuffer_reset_to_saved'
function we must restore the default state of the batch using
'brw_new_batch' function because the 'intel_batchbuffer_flush'
function will not do it for the 'new batch' again.
At least the following fields of the batch
'state_base_address_emitted','aperture_space', 'state_used'
should be restored to default values to avoid:
1. the aperture_space overflow
2. the missed STATE_BASE_ADDRESS commad in the batch
3. the memory overconsumption of the 'statebuffer'
   due to uncleared 'state_used' field.
etc.

Signed-off-by: Andrii Simiklit <andrii.simiklit at globallogic.com>
---
 src/mesa/drivers/dri/i965/intel_batchbuffer.c | 104 +++++++++++++++-----------
 1 file changed, 59 insertions(+), 45 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_batchbuffer.c b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
index 65d2c64..b8c5fb4 100644
--- a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
+++ b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
@@ -219,7 +219,7 @@ add_exec_bo(struct intel_batchbuffer *batch, struct brw_bo *bo)
    bo->index = batch->exec_count;
    batch->exec_bos[batch->exec_count] = bo;
    batch->aperture_space += bo->size;
-
+   assert((batch->aperture_space >= 0) && "error 'batch->aperture_space' field is overflown!");
    return batch->exec_count++;
 }
 
@@ -290,6 +290,51 @@ intel_batchbuffer_reset_and_clear_render_cache(struct brw_context *brw)
    brw_cache_sets_clear(brw);
 }
 
+/**
+ * Called when starting a new batch buffer.
+ */
+static void
+brw_new_batch(struct brw_context *brw)
+{
+   /* Unreference any BOs held by the previous batch, and reset counts. */
+   for (int i = 0; i < brw->batch.exec_count; i++) {
+      brw_bo_unreference(brw->batch.exec_bos[i]);
+      brw->batch.exec_bos[i] = NULL;
+   }
+   brw->batch.batch_relocs.reloc_count = 0;
+   brw->batch.state_relocs.reloc_count = 0;
+   brw->batch.exec_count = 0;
+   brw->batch.aperture_space = 0;
+
+   brw_bo_unreference(brw->batch.state.bo);
+
+   /* Create a new batchbuffer and reset the associated state: */
+   intel_batchbuffer_reset_and_clear_render_cache(brw);
+
+   /* If the kernel supports hardware contexts, then most hardware state is
+    * preserved between batches; we only need to re-emit state that is required
+    * to be in every batch.  Otherwise we need to re-emit all the state that
+    * would otherwise be stored in the context (which for all intents and
+    * purposes means everything).
+    */
+   if (brw->hw_ctx == 0) {
+      brw->ctx.NewDriverState |= BRW_NEW_CONTEXT;
+      brw_upload_invariant_state(brw);
+   }
+
+   brw->ctx.NewDriverState |= BRW_NEW_BATCH;
+
+   brw->ib.index_size = -1;
+
+   /* We need to periodically reap the shader time results, because rollover
+    * happens every few seconds.  We also want to see results every once in a
+    * while, because many programs won't cleanly destroy our context, so the
+    * end-of-run printout may not happen.
+    */
+   if (INTEL_DEBUG & DEBUG_SHADER_TIME)
+      brw_collect_and_report_shader_time(brw);
+}
+
 void
 intel_batchbuffer_save_state(struct brw_context *brw)
 {
@@ -311,6 +356,19 @@ intel_batchbuffer_reset_to_saved(struct brw_context *brw)
    brw->batch.exec_count = brw->batch.saved.exec_count;
 
    brw->batch.map_next = brw->batch.saved.map_next;
+   if (USED_BATCH(brw->batch) == 0)
+   {
+      /**
+       * The 'intel_batchbuffer_flush' function will not call
+       * the 'brw_new_batch' function when the USED_BATCH returns 0.
+       * It may leads to the few following issue:
+       * The 'aperture_space' field can be overflown
+       * The 'statebuffer' buffer contains the big unused space
+       * The STATE_BASE_ADDRESS message is missed
+       * etc
+       **/
+      brw_new_batch(brw);
+   }
 }
 
 void
@@ -529,50 +587,6 @@ intel_batchbuffer_require_space(struct brw_context *brw, GLuint sz)
    }
 }
 
-/**
- * Called when starting a new batch buffer.
- */
-static void
-brw_new_batch(struct brw_context *brw)
-{
-   /* Unreference any BOs held by the previous batch, and reset counts. */
-   for (int i = 0; i < brw->batch.exec_count; i++) {
-      brw_bo_unreference(brw->batch.exec_bos[i]);
-      brw->batch.exec_bos[i] = NULL;
-   }
-   brw->batch.batch_relocs.reloc_count = 0;
-   brw->batch.state_relocs.reloc_count = 0;
-   brw->batch.exec_count = 0;
-   brw->batch.aperture_space = 0;
-
-   brw_bo_unreference(brw->batch.state.bo);
-
-   /* Create a new batchbuffer and reset the associated state: */
-   intel_batchbuffer_reset_and_clear_render_cache(brw);
-
-   /* If the kernel supports hardware contexts, then most hardware state is
-    * preserved between batches; we only need to re-emit state that is required
-    * to be in every batch.  Otherwise we need to re-emit all the state that
-    * would otherwise be stored in the context (which for all intents and
-    * purposes means everything).
-    */
-   if (brw->hw_ctx == 0) {
-      brw->ctx.NewDriverState |= BRW_NEW_CONTEXT;
-      brw_upload_invariant_state(brw);
-   }
-
-   brw->ctx.NewDriverState |= BRW_NEW_BATCH;
-
-   brw->ib.index_size = -1;
-
-   /* We need to periodically reap the shader time results, because rollover
-    * happens every few seconds.  We also want to see results every once in a
-    * while, because many programs won't cleanly destroy our context, so the
-    * end-of-run printout may not happen.
-    */
-   if (INTEL_DEBUG & DEBUG_SHADER_TIME)
-      brw_collect_and_report_shader_time(brw);
-}
 
 /**
  * Called from intel_batchbuffer_flush before emitting MI_BATCHBUFFER_END and
-- 
2.7.4