radeonsi: make sure CP DMA is idle at the end of IBs

diff --git a/src/gallium/drivers/radeonsi/si_cp_dma.c b/src/gallium/drivers/radeonsi/si_cp_dma.c
index 358b33c..b316637 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_cp_dma.c
+++ b/src/gallium/drivers/radeonsi/si_cp_dma.c
@@ -65,7 +65,6 @@ static void si_emit_cp_dma(struct si_context *sctx, uint64_t dst_va,
        struct radeon_winsys_cs *cs = sctx->gfx_cs;
        uint32_t header = 0, command = 0;
 
-       assert(size);
        assert(size <= cp_dma_max_byte_count(sctx));
 
        if (sctx->chip_class >= GFX9)
@@ -128,6 +127,17 @@ static void si_emit_cp_dma(struct si_context *sctx, uint64_t dst_va,
        }
 }
 
+void si_cp_dma_wait_for_idle(struct si_context *sctx)
+{
+       /* Issue a dummy DMA that copies zero bytes.
+        *
+        * The DMA engine will see that there's no work to do and skip this
+        * DMA request, however, the CP will see the sync flag and still wait
+        * for all DMAs to complete.
+        */
+       si_emit_cp_dma(sctx, 0, 0, 0, CP_DMA_SYNC, SI_COHERENCY_NONE);
+}
+
 static unsigned get_flush_flags(struct si_context *sctx, enum si_coherency coher)
 {
        switch (coher) {

diff --git a/src/gallium/drivers/radeonsi/si_gfx_cs.c b/src/gallium/drivers/radeonsi/si_gfx_cs.c
index f99bc32..2d5e510 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_gfx_cs.c
+++ b/src/gallium/drivers/radeonsi/si_gfx_cs.c
@@ -111,7 +111,10 @@ void si_flush_gfx_cs(struct si_context *ctx, unsigned flags,
                ctx->flags |= SI_CONTEXT_INV_GLOBAL_L2 |
                                SI_CONTEXT_INV_VMEM_L1;
 
-       si_emit_cache_flush(ctx);
+       /* Make sure CP DMA is idle at the end of IBs after L2 prefetches
+        * because the kernel doesn't wait for it. */
+       if (ctx->chip_class >= CIK)
+               si_cp_dma_wait_for_idle(ctx);
 
        if (ctx->current_saved_cs) {
                si_trace_emit(ctx);

diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index c7ad536..3a2f7ca 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -902,6 +902,7 @@ enum si_coherency {
        SI_COHERENCY_CB_META,
 };
 
+void si_cp_dma_wait_for_idle(struct si_context *sctx);
 void si_clear_buffer(struct si_context *sctx, struct pipe_resource *dst,
                     uint64_t offset, uint64_t size, unsigned value,
                     enum si_coherency coher);