From: Chris Wilson Date: Thu, 29 Aug 2019 08:11:15 +0000 (+0100) Subject: drm/i915/execlists: Try rearranging breadcrumb flush X-Git-Tag: v5.5-rc1~128^2~32^2~270 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=11988e393813f520974f69bf0e55c367a1cbac48;p=thirdparty%2Fkernel%2Flinux.git 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: e8f6b4952ec5 ("drm/i915/execlists: Flush the post-sync breadcrumb write harder") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Acked-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190829081150.10271-2-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 171d5205962c0..7d460b1842ddd 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -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_FLUSH_ENABLE | + PIPE_CONTROL_CS_STALL); return gen8_emit_fini_breadcrumb_footer(request, cs); }