[PATCH 1/2] drm/i915: Unset legacy_cursor_update early in intel_atomic_commit, v3.

Maarten Lankhorst
2017-09-19T12:14:25Z

Commit b44d5c0c105a ("drm/i915: Always wait for flip_done, v2.") removed
the call to wait_for_vblanks and replaced it with flip_done.

Unfortunately legacy_cursor_update was unset too late, and the
replacement call drm_atomic_helper_wait_for_flip_done() was
a noop. Make sure that its unset before setup_commit() is
called to fix this issue.

Changes since v1:
- Force vblank wait for watermarks not yet converted to atomic too. (Ville)
- Use for_each_new_intel_crtc_in_state. (Ville)
Changes since v2:
- Move the optimization to a separate commit. (Ville)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: b44d5c0c105a ("drm/i915: Always wait for flip_done, v2.")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102675
Testcase: kms_cursor_crc
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reported-by: Marta Löfstedt <marta.lofstedt@intel.com>
Cc: Marta Löfstedt <marta.lofstedt@intel.com>
Tested-by: Marta Löfstedt <marta.lofstedt@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8599e425abb1..a85ca19a0c45 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12517,21 +12517,10 @@ static int intel_atomic_commit(struct drm_device *dev,
struct drm_i915_private *dev_priv = to_i915(dev);
int ret = 0;

- ret = drm_atomic_helper_setup_commit(state, nonblock);
- if (ret)
- return ret;
-
drm_atomic_state_get(state);
i915_sw_fence_init(&intel_state->commit_ready,
intel_atomic_commit_ready);

- ret = intel_atomic_prepare_commit(dev, state);
- if (ret) {
- DRM_DEBUG_ATOMIC("Preparing state failed with %i\n", ret);
- i915_sw_fence_commit(&intel_state->commit_ready);
- return ret;
- }
-
/*
* The intel_legacy_cursor_update() fast path takes care
* of avoiding the vblank waits for simple cursor
@@ -12540,11 +12529,11 @@ static int intel_atomic_commit(struct drm_device *dev,
* updates happen during the correct frames. Gen9+ have
* double buffered watermarks and so shouldn't need this.
*
- * Do this after drm_atomic_helper_setup_commit() and
- * intel_atomic_prepare_commit() because we still want
- * to skip the flip and fb cleanup waits. Although that
- * does risk yanking the mapping from under the display
- * engine.
+ * Unset state->legacy_cursor_update before the call to
+ * drm_atomic_helper_setup_commit() because otherwise
+ * drm_atomic_helper_wait_for_flip_done() is a noop and
+ * we get FIFO underruns because we didn't wait
+ * for vblank.
*
* FIXME doing watermarks and fb cleanup from a vblank worker
* (assuming we had any) would solve these problems.
@@ -12552,7 +12541,17 @@ static int intel_atomic_commit(struct drm_device *dev,
if (INTEL_GEN(dev_priv) < 9)
state->legacy_cursor_update = false;

- ret = drm_atomic_helper_swap_state(state, true);
+ ret = intel_atomic_prepare_commit(dev, state);
+ if (ret) {
+ DRM_DEBUG_ATOMIC("Preparing state failed with %i\n", ret);
+ i915_sw_fence_commit(&intel_state->commit_ready);
+ return ret;
+ }
+
+ ret = drm_atomic_helper_setup_commit(state, nonblock);
+ if (!ret)
+ ret = drm_atomic_helper_swap_state(state, true);
+
if (ret) {
i915_sw_fence_commit(&intel_state->commit_ready);

--
2.14.1