4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Francisco Jerez <[email protected]> commit 935a0ff0e1ea62a116848c0a187b13838f7b9cee upstream. We need to set the DC FLUSH PIPE_CONTROL bit on Gen7+ to guarantee that writes performed via the HDC are visible in memory. Fixes an intermittent failure in a Piglit test that writes to a BO from a shader using GL atomic counters (implemented as HDC untyped atomics) and then expects the memory to read back the same value after mapping it on the CPU. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91298 Tested-by: Mark Janes <[email protected]> Cc: Rodrigo Vivi <[email protected]> Signed-off-by: Francisco Jerez <[email protected]> Reviewed-by: Ville Syrjälä <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] (cherry picked from commit 965fd602a6436f689f4f2fe40a6789582778ccd5) Signed-off-by: Jani Nikula <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/i915/intel_lrc.c | 1 + drivers/gpu/drm/i915/intel_ringbuffer.c | 2 ++ 2 files changed, 3 insertions(+) --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1706,6 +1706,7 @@ static int gen8_emit_flush_render(struct if (flush_domains) { flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH; flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH; + flags |= PIPE_CONTROL_DC_FLUSH_ENABLE; flags |= PIPE_CONTROL_FLUSH_ENABLE; } --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -347,6 +347,7 @@ gen7_render_ring_flush(struct drm_i915_g if (flush_domains) { flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH; flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH; + flags |= PIPE_CONTROL_DC_FLUSH_ENABLE; flags |= PIPE_CONTROL_FLUSH_ENABLE; } if (invalidate_domains) { @@ -419,6 +420,7 @@ gen8_render_ring_flush(struct drm_i915_g if (flush_domains) { flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH; flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH; + flags |= PIPE_CONTROL_DC_FLUSH_ENABLE; flags |= PIPE_CONTROL_FLUSH_ENABLE; } if (invalidate_domains) {
