The predicate source registers are needed to implement conditional rendering without stalling. The two source registers are used to load the previous values of the PS_DEPTH_COUNT register saved from PIPE_CONTROL commands. These can then be compared and used to set the predicate enable bit via the MI_PREDICATE command.
Signed-off-by: Neil Roberts <[email protected]> --- There is a corresponding patch for Mesa which is using these registers on the mailing list here: http://lists.freedesktop.org/archives/mesa-dev/2014-November/070347.html There are some other registers such as MI_PREDICATE_DATA which can be used for more advanced predicate checking but I haven't added them to the list because they aren't needed to implement GL_NV_conditional_render. drivers/gpu/drm/i915/i915_cmd_parser.c | 2 ++ drivers/gpu/drm/i915/i915_reg.h | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 4c35e2a..9732155 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -408,6 +408,8 @@ static const u32 gen7_render_regs[] = { REG64(PS_INVOCATION_COUNT), REG64(PS_DEPTH_COUNT), OACONTROL, /* Only allowed for LRI and SRM. See below. */ + REG64(MI_PREDICATE_SRC0), + REG64(MI_PREDICATE_SRC1), GEN7_3DPRIM_END_OFFSET, GEN7_3DPRIM_START_VERTEX, GEN7_3DPRIM_VERTEX_COUNT, diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index ea84e1e..9275d41 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -314,6 +314,8 @@ #define MI_BATCH_GTT (2<<6) /* aliased with (1<<7) on gen4 */ #define MI_BATCH_BUFFER_START_GEN8 MI_INSTR(0x31, 1) +#define MI_PREDICATE_SRC0 (0x2400) +#define MI_PREDICATE_SRC1 (0x2408) #define MI_PREDICATE_RESULT_2 (0x2214) #define LOWER_SLICE_ENABLED (1<<0) -- 1.9.3 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
