[Intel-gfx] [PATCH] drm/i915: Use mmio flips harder

[Daniel Vetter]

Somehow (i.e. purely experimental evidence from users out there in the
wild) using CS flips seems to be implicated in hw context switch
hangs.

I have no idea why, but let's just try this out.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78960
References: https://bugs.freedesktop.org/show_bug.cgi?id=83677
References: https://bugs.freedesktop.org/show_bug.cgi?id=80660
References: https://bugs.freedesktop.org/show_bug.cgi?id=76314
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a4106049e158..e5ece609e9fc 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9462,6 +9462,8 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
 		return true;
 	else if (i915.enable_execlists)
 		return true;
+	else if (INTEL_FINO(ring->dev)->gen >= 6)
+		return true;
 	else
 		return ring != obj->ring;
 }
-- 
2.1.1