From 7b36c68ba6899c7f30fd56b7ef07a78b027771ac Mon Sep 17 00:00:00 2001 From: Chad Versace Date: Thu, 26 Jan 2012 11:01:36 -0800 Subject: i965: Rewrite the HiZ op The HiZ op was implemented as a meta-op. This patch reimplements it by emitting a special HiZ batch. This fixes several known bugs, and likely a lot of undiscovered ones too. ==== Why the HiZ meta-op needed to die ==== The HiZ op was implemented as a meta-op, which caused lots of trouble. All other meta-ops occur as a result of some GL call (for example, glClear and glGenerateMipmap), but the HiZ meta-op was special. It was called in places that Mesa (in particular, the vbo and swrast modules) did not expect---and were not prepared for---state changes to occur (for example: glDraw; glCallList; within glBegin/End blocks; and within swrast_prepare_render as a result of intel_miptree_map). In an attempt to work around these unexpected state changes, I added two hooks in i965: - A hook for glDraw, located in brw_predraw_resolve_buffers (which is called in the glDraw path). This hook detected if a predraw resolve meta-op had occurred, and would hackishly repropagate some GL state if necessary. This ensured that the meta-op state changes would not intefere with the vbo module's subsequent execution of glDraw. - A hook for glBegin, implemented by brwPrepareExecBegin. This hook resolved all buffers before entering a glBegin/End block, thus preventing an infinitely recurring call to vbo_exec_FlushVertices. The vbo module calls vbo_exec_FlushVertices to flush its vertex queue in response to GL state changes. Unfortunately, these hooks were not sufficient. The meta-op state changes still interacted badly with glPopAttrib (as discovered in bug 44927) and with swrast rendering (as discovered by debugging gen6's swrast fallback for glBitmap). I expect there are more undiscovered bugs. Rather than play whack-a-mole in a minefield, the sane approach is to replace the HiZ meta-op with something safer. ==== How it was killed ==== This patch consists of several logical components: 1. Rewrite the HiZ op by replacing function gen6_resolve_slice with gen6_hiz_exec and gen7_hiz_exec. The new functions do not call a meta-op, but instead manually construct and emit a batch to "draw" the HiZ op's rectangle primitive. The new functions alter no GL state. 2. Add fields to brw_context::hiz for the new HiZ op. 3. Emit a workaround flush when toggling 3DSTATE_VS.VsFunctionEnable. 4. Kill all dead HiZ code: - the function gen6_resolve_slice - the dirty flag BRW_NEW_HIZ - the dead fields in brw_context::hiz - the state packet manipulation triggered by the now removed brw_context::hiz::op - the meta-op workaround in brw_predraw_resolve_buffers (discussed above) - the meta-op workaround brwPrepareExecBegin (discussed above) Note: This is a candidate for the 8.0 branch. Reviewed-by: Eric Anholt Reviewed-by: Kenneth Graunke Acked-by: Paul Berry Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43327 Reported-by: xunx.fang@intel.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44927 Reported-by: chao.a.chen@intel.com Signed-off-by: Chad Versace --- src/mesa/drivers/dri/i965/gen6_sf_state.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'src/mesa/drivers/dri/i965/gen6_sf_state.c') diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c b/src/mesa/drivers/dri/i965/gen6_sf_state.c index 163b54c..07b8e6d 100644 --- a/src/mesa/drivers/dri/i965/gen6_sf_state.c +++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c @@ -149,17 +149,8 @@ upload_sf_state(struct brw_context *brw) urb_entry_read_length << GEN6_SF_URB_ENTRY_READ_LENGTH_SHIFT | urb_entry_read_offset << GEN6_SF_URB_ENTRY_READ_OFFSET_SHIFT; - dw2 = GEN6_SF_STATISTICS_ENABLE; - - /* Enable viewport transform only if no HiZ operation is progress - * - * From page 11 of the SandyBridge PRM, Volume 2, Part 1, Section 1.3, "3D - * Primitives Overview": - * RECTLIST: Viewport Mapping must be DISABLED (as is typical with the - * use of screen- space coordinates). - */ - if (!brw->hiz.op) - dw2 |= GEN6_SF_VIEWPORT_TRANSFORM_ENABLE; + dw2 = GEN6_SF_STATISTICS_ENABLE | + GEN6_SF_VIEWPORT_TRANSFORM_ENABLE; dw3 = 0; dw4 = 0; @@ -354,8 +345,7 @@ const struct brw_tracked_state gen6_sf_state = { _NEW_POINT | _NEW_TRANSFORM), .brw = (BRW_NEW_CONTEXT | - BRW_NEW_FRAGMENT_PROGRAM | - BRW_NEW_HIZ), + BRW_NEW_FRAGMENT_PROGRAM), .cache = CACHE_NEW_VS_PROG }, .emit = upload_sf_state, -- cgit v1.1