Hi Tejas, On Wed, May 31, 2023 at 08:02:14PM +0530, Tejas Upadhyay wrote: > Wa_14016712196 implementation for mtl > > Bspec: 72197 > > V3: > - Wrap dummy pipe control stuff in API - Andi > V2: > - Fix kernel test robot warnings > > Closes: https://lore.kernel.org/oe-kbuild-all/202305121525.3EWdGoBY-lkp@xxxxxxxxx/ > Signed-off-by: Tejas Upadhyay <tejas.upadhyay@xxxxxxxxx> > --- > drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 39 ++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > index e1c76e5bfa82..206947f1fc7c 100644 > --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > @@ -177,6 +177,30 @@ u32 *gen12_emit_aux_table_inv(struct intel_gt *gt, u32 *cs, const i915_reg_t inv > return cs; > } > > +static u32 *mtl_dummy_pipe_control(struct i915_request *rq) > +{ > + u32 *cs; > + > + /* Wa_14016712196 */ > + if (IS_MTL_GRAPHICS_STEP(rq->engine->i915, M, STEP_A0, STEP_B0) || > + IS_MTL_GRAPHICS_STEP(rq->engine->i915, P, STEP_A0, STEP_B0)) { > + int ret; > + > + /* dummy PIPE_CONTROL + depth flush */ > + cs = intel_ring_begin(rq, 6); > + ret = IS_ERR(cs); > + if (ret) > + return ERR_PTR(ret); > + cs = gen12_emit_pipe_control(cs, > + 0, > + PIPE_CONTROL_DEPTH_CACHE_FLUSH, > + LRC_PPHWSP_SCRATCH_ADDR); > + intel_ring_advance(rq, cs); > + } > + > + return cs; mmmhhh... the value of cs at the end is not used, unless it's an error. Isn't it better to just have this function as a "static int" that returns '0' or -errno? This might also confuse some static analyzers, I guess. Andi > +} > + > int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode) > { > struct intel_engine_cs *engine = rq->engine; > @@ -185,6 +209,10 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode) > u32 flags = 0; > u32 *cs; > > + cs = mtl_dummy_pipe_control(rq); > + if (IS_ERR(cs)) > + return PTR_ERR(cs); > + > flags |= PIPE_CONTROL_TILE_CACHE_FLUSH; > flags |= PIPE_CONTROL_FLUSH_L3; > flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH; > @@ -218,6 +246,10 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode) > u32 flags = 0; > u32 *cs, count; > > + cs = mtl_dummy_pipe_control(rq); > + if (IS_ERR(cs)) > + return PTR_ERR(cs); > + > flags |= PIPE_CONTROL_COMMAND_CACHE_INVALIDATE; > flags |= PIPE_CONTROL_TLB_INVALIDATE; > flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE; > @@ -733,6 +765,13 @@ u32 *gen12_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs) > PIPE_CONTROL_DC_FLUSH_ENABLE | > PIPE_CONTROL_FLUSH_ENABLE); > > + /* Wa_14016712196 */ > + if (IS_MTL_GRAPHICS_STEP(i915, M, STEP_A0, STEP_B0) || > + IS_MTL_GRAPHICS_STEP(i915, P, STEP_A0, STEP_B0)) > + /* dummy PIPE_CONTROL + depth flush */ > + cs = gen12_emit_pipe_control(cs, 0, > + PIPE_CONTROL_DEPTH_CACHE_FLUSH, 0); > + > if (GRAPHICS_VER(i915) == 12 && GRAPHICS_VER_FULL(i915) < IP_VER(12, 50)) > /* Wa_1409600907 */ > flags |= PIPE_CONTROL_DEPTH_STALL; > -- > 2.25.1