Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > In a simple test case that writes to scratch and then busy-waits for the > batch to be signaled, we observe that the signal is before the write is > posted. That is bad news. > > Splitting the flush + write_dword into two separate flush_dw prevents > the issue from being reproduced, we can presume the post-sync op is not > so post-sync. > Only thing that is mildly surpricing is that first one doesnt need postop write. > Testcase: igt/gem_exec_fence/parallel > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Acked-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index d0be98b67138..a437140a987d 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -5047,7 +5047,8 @@ gen12_emit_fini_breadcrumb_tail(struct i915_request *request, u32 *cs) > > static u32 *gen12_emit_fini_breadcrumb(struct i915_request *rq, u32 *cs) > { > - return gen12_emit_fini_breadcrumb_tail(rq, emit_xcs_breadcrumb(rq, cs)); > + cs = emit_xcs_breadcrumb(rq, __gen8_emit_flush_dw(cs, 0, 0, 0)); > + return gen12_emit_fini_breadcrumb_tail(rq, cs); > } > > static u32 * > -- > 2.20.1