[Intel-gfx] [PATCH] drm/i915: Don't forget to reset blocks when testing lower wm levels

[Matt Roper]

During DDB allocation, we try to distribute enough blocks for each plane
to hit the highest watermark level; if that fails, we retry each lower
level (which should require fewer blocks) until we find one that's
possible (or until the whole commit is rejected as impossible).  We need
to reset our running block count when trying each lower level, otherwise
all lower levels will fail as well.

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Fixes: d8e8749802 ("drm/i915: Switch to level-based DDB allocation algorithm (v5)")
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
After waiting for CI results to come out, I accidentally pushed v5 of
the new DDB algorithm rather than the expected v6.  This fixup patch is
the only difference between those two versions.

 drivers/gpu/drm/i915/intel_pm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 6d074f2e69d3..a6c7c11d2c0e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4365,6 +4365,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 	 * requirement of active planes.
 	 */
 	for (level = ilk_wm_max_level(dev_priv); level >= 0; level--) {
+		blocks = 0;
 		for_each_plane_id_on_crtc(intel_crtc, plane_id) {
 			if (plane_id == PLANE_CURSOR)
 				continue;
-- 
2.14.4