drm/i915: hold forcewake around ring hw init
Empirical evidence suggests that we need to: On at least one ivb
machine when running the hangman i-g-t test, the rings don't properly
initialize properly - the RING_START registers seems to be stuck at
all zeros.
Holding forcewake around this register init sequences makes chip reset
reliable again. Note that this is not the first such issue:
commit f01db988ef6f6c70a6cc36ee71e4a98a68901229
Author: Sean Paul <seanpaul@chromium.org>
Date: Fri Mar 16 12:43:22 2012 -0400
drm/i915: Add wait_for in init_ring_common
added delay loops to make RING_START and RING_CTL initialization
reliable on the blt ring at boot-up. So I guess it won't hurt if we do
this unconditionally for all force_wake needing gpus.
To avoid copy&pasting of the HAS_FORCE_WAKE check I've added a new
intel_info bit for that.
v2: Fixup missing commas in static struct and properly handling the
error case in init_ring_common, both noticed by Jani Nikula.
Cc: stable@vger.kernel.org
Reported-and-tested-by: Yang Guang <guang.a.yang@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 377c21f..cff6307 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -285,6 +285,7 @@
u8 is_ivybridge:1;
u8 is_valleyview:1;
u8 has_pch_split:1;
+ u8 has_force_wake:1;
u8 is_haswell:1;
u8 has_fbc:1;
u8 has_pipe_cxsr:1;
@@ -1098,6 +1099,8 @@
#define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)
#define HAS_PCH_IBX(dev) (INTEL_PCH_TYPE(dev) == PCH_IBX)
+#define HAS_FORCE_WAKE(dev) (INTEL_INFO(dev)->has_force_wake)
+
#include "i915_trace.h"
/**