[Intel-gfx] [PATCH 4/4] drm/i915: Clear crtc atomic flags at beginning of transaction

[Matt Roper]

Once we have full atomic modeset, these kind of flags should be in a
real intel_crtc_state that's tracked properly.  In the meantime, make
sure we clear out any old flags at the beginning of a transaction so
that we don't wind up seeing leftover flags from old transactions that
were checked, but never went to the commit step.

A simple memset would have done here, but I expect there to be a few
more things that we *don't* want to clear that get added into this
structure before we're ready to kill off and roll everything into the
CRTC state.

Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/intel_atomic.c  | 18 ++++++++++++++++++
 drivers/gpu/drm/i915/intel_display.c |  2 +-
 drivers/gpu/drm/i915/intel_drv.h     |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
index 3903b90..542230d 100644
--- a/drivers/gpu/drm/i915/intel_atomic.c
+++ b/drivers/gpu/drm/i915/intel_atomic.c
@@ -35,6 +35,22 @@
 #include <drm/drm_plane_helper.h>
 #include "intel_drv.h"
 
+/**
+ * intel_clear_atomic_crtc_flags
+ * @crtc: CRTC to clear flags for
+ *
+ * Until we have proper atomic handling of CRTC states, we dump some atomic
+ * task flags in intel_crtc->atomic.  Those flags need to be cleared at
+ * the beginning of each transaction so that we don't carry over stale flags
+ * from previous transactions.
+ *
+ * Note that the whole intel_crtc->atomic structure is a temporary hack and
+ * should transition into the CRTC state eventually.
+ */
+void intel_clear_atomic_crtc_flags(struct intel_crtc *crtc)
+{
+	memset(&crtc->atomic, 0, sizeof(crtc->atomic));
+}
 
 /**
  * intel_atomic_check - validate state object
@@ -76,6 +92,8 @@ int intel_atomic_check(struct drm_device *dev,
 	state->allow_modeset = false;
 	for (i = 0; i < ncrtcs; i++) {
 		struct intel_crtc *crtc = to_intel_crtc(state->crtcs[i]);
+		if (crtc)
+			intel_clear_atomic_crtc_flags(crtc);
 		if (crtc && crtc->pipe != nuclear_pipe)
 			not_nuclear = true;
 	}
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3a74923..bb8d345 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12812,7 +12812,7 @@ static void intel_finish_crtc_commit(struct drm_crtc *crtc)
 			intel_update_sprite_watermarks(p, crtc, 0, 0, 0,
 						       false, false);
 
-	memset(&intel_crtc->atomic, 0, sizeof(intel_crtc->atomic));
+	intel_clear_atomic_crtc_flags(intel_crtc);
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index d5ea24f..28d838e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1303,6 +1303,7 @@ void intel_pre_disable_primary(struct drm_crtc *crtc);
 void intel_tv_init(struct drm_device *dev);
 
 /* intel_atomic.c */
+void intel_clear_atomic_crtc_flags(struct intel_crtc *crtc);
 int intel_atomic_check(struct drm_device *dev,
 		       struct drm_atomic_state *state);
 int intel_atomic_commit(struct drm_device *dev,
-- 
1.8.5.1