[PATCH 28/31] drm/vc4: hvs: Rework LBM alignment

Dave Stevenson dave.stevenson at raspberrypi.com
Thu Jun 20 15:46:29 UTC 2024


From: Maxime Ripard <maxime at cerno.tech>

With the introduction of the support for BCM2712, the check of whether
we're running on vc5 or not to compute the LBM alignment requirement
doesn't work anymore.

Moreover, the LBM size will need to be computed in words for the
BCM2712, while we've had sizes in bytes so far.

Aligning on either 64 or 32 words is thus fairly harmful on BCM2712, so
let's just explicitly align the size when needed, and then call
drm_mm_insert_node_generic() with an alignment of 1.

Signed-off-by: Maxime Ripard <mripard at kernel.org>
Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_plane.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index a4965226595d..4c61ef4f4142 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -756,6 +756,11 @@ static int vc4_plane_allocate_lbm(struct drm_plane_state *state)
 	if (!lbm_size)
 		return 0;
 
+	if (vc4->gen == VC4_GEN_5)
+		lbm_size = ALIGN(lbm_size, 64);
+	else if (vc4->gen == VC4_GEN_4)
+		lbm_size = ALIGN(lbm_size, 32);
+
 	drm_dbg_driver(drm, "[PLANE:%d:%s] LBM Allocation Size: %u\n",
 		       plane->base.id, plane->name, lbm_size);
 
@@ -771,8 +776,7 @@ static int vc4_plane_allocate_lbm(struct drm_plane_state *state)
 		spin_lock_irqsave(&vc4->hvs->mm_lock, irqflags);
 		ret = drm_mm_insert_node_generic(&vc4->hvs->lbm_mm,
 						 &vc4_state->lbm,
-						 lbm_size,
-						 vc4->gen == VC4_GEN_5 ? 64 : 32,
+						 lbm_size, 1,
 						 0, 0);
 		spin_unlock_irqrestore(&vc4->hvs->mm_lock, irqflags);
 
-- 
2.34.1



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