[RFC PATCH 7/8] drm/i915: Calculate ironlake intermediate watermarks correctly, v2.

Maarten Lankhorst
2017-07-20T13:15:27Z

The watermarks it should calculate against are the old optimal watermarks.
The currently active crtc watermarks are pure fiction, and are invalid in
case of a nonblocking modeset, page flip enabling/disabling planes or any
other reason.

When the crtc is disabled or during a modeset the intermediate watermarks
don't need to be programmed separately, and could be directly assigned
to the optimal watermarks.

Changes since v1:
- Use intel_atomic_get_old_crtc_state. (ville)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
drivers/gpu/drm/i915/intel_pm.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 0cdb9453e0e2..0048bf043337 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3105,7 +3105,9 @@ static int ilk_compute_intermediate_wm(struct drm_device *dev,
struct intel_crtc_state *newstate)
{
struct intel_pipe_wm *a = &newstate->wm.ilk.intermediate;
- struct intel_pipe_wm *b = &intel_crtc->wm.active.ilk;
+ const struct intel_crtc_state *oldstate =
+ intel_atomic_get_old_crtc_state(newstate->base.state, intel_crtc);
+ const struct intel_pipe_wm *b = &oldstate->wm.ilk.optimal;
int level, max_level = ilk_wm_max_level(to_i915(dev));

/*
@@ -3114,6 +3116,9 @@ static int ilk_compute_intermediate_wm(struct drm_device *dev,
* and after the vblank.
*/
*a = newstate->wm.ilk.optimal;
+ if (!newstate->base.active || drm_atomic_crtc_needs_modeset(&newstate->base))
+ return 0;
+
a->pipe_enabled |= b->pipe_enabled;
a->sprites_enabled |= b->sprites_enabled;
a->sprites_scaled |= b->sprites_scaled;