drm/i915/execlists: Try rearranging breadcrumb flush

The addition of the DC_FLUSH failed to ensure sanctity of the post-sync
write as CI immediately got a completion CS-event before the breadcrumb
was coherent. So let's try the other idea of moving the post-sync write
into the CS_STALL.

References: https://bugs.freedesktop.org/show_bug.cgi?id=111514
References: e8f6b4952e ("drm/i915/execlists: Flush the post-sync breadcrumb write harder")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190829081150.10271-2-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2019-08-29 09:11:15 +01:00
parent 66d9cec8a6
commit 11988e3938

View File

@ -2915,20 +2915,18 @@ static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
{
cs = gen8_emit_pipe_control(cs,
PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
PIPE_CONTROL_DEPTH_CACHE_FLUSH |
PIPE_CONTROL_DC_FLUSH_ENABLE,
0);
/* XXX flush+write+CS_STALL all in one upsets gem_concurrent_blt:kbl */
cs = gen8_emit_ggtt_write_rcs(cs,
request->fence.seqno,
request->timeline->hwsp_offset,
PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
PIPE_CONTROL_DEPTH_CACHE_FLUSH |
PIPE_CONTROL_DC_FLUSH_ENABLE);
/* XXX flush+write+CS_STALL all in one upsets gem_concurrent_blt:kbl */
/* XXX DC_FLUSH for post-sync write? (cf early context-switch bug) */
cs = gen8_emit_pipe_control(cs,
PIPE_CONTROL_FLUSH_ENABLE |
PIPE_CONTROL_DC_FLUSH_ENABLE |
PIPE_CONTROL_CS_STALL,
0);
PIPE_CONTROL_CS_STALL);
return gen8_emit_fini_breadcrumb_footer(request, cs);
}