From ecb98c68988570806c239c7cc705c69a98aafc23 Mon Sep 17 00:00:00 2001 From: Danylo Piliaiev Date: Mon, 18 Mar 2019 12:53:30 +0200 Subject: [PATCH] anv: Treat zero size XFB buffer as disabled Vulkan spec doesn't explicitly forbid zero size transform feedback buffers. Having zero size xfb caused SurfaceSize overflow and triggered assert in debug build. The only way to have zero size SO_BUFFER is to disable SO_BUFFER as stated in hardware spec. From SKL PRM, Vol 2a, "3DSTATE_SO_BUFFER": "If set, stream output to SO Buffer is enabled, if 3DSTATE_STREAMOUT::SO Function ENABLE is also enabled. If clear, the SO Buffer is considered "not bound" and effectively treated as a zero- length buffer for the purposes of SO output and overflow detection. If an enabled stream's Stream to Buffer Selects includes this buffer it is by definition an overflow condition. That stream will cause no writes to occur, and only SO_PRIM_STORAGE_NEEDED[] will increment." Fixes: 36ee2fd61c8 "anv: Implement the basic form of VK_EXT_transform_feedback" Signed-off-by: Danylo Piliaiev Reviewed-by: Lionel Landwerlin Reviewed-by: Jason Ekstrand --- src/intel/vulkan/genX_cmd_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c index 7687507e6b7..e5daf8b037d 100644 --- a/src/intel/vulkan/genX_cmd_buffer.c +++ b/src/intel/vulkan/genX_cmd_buffer.c @@ -2702,7 +2702,7 @@ genX(cmd_buffer_flush_state)(struct anv_cmd_buffer *cmd_buffer) anv_batch_emit(&cmd_buffer->batch, GENX(3DSTATE_SO_BUFFER), sob) { sob.SOBufferIndex = idx; - if (cmd_buffer->state.xfb_enabled && xfb->buffer) { + if (cmd_buffer->state.xfb_enabled && xfb->buffer && xfb->size != 0) { sob.SOBufferEnable = true; sob.MOCS = cmd_buffer->device->default_mocs, sob.StreamOffsetWriteEnable = false; -- 2.30.2