drm: rcar-du: Add plane allocation debugging

Plane allocation is a complex process, add debugging statements to help
finding out what could might wrong.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 14d457047c404019622bbf11ad44cdace927eba3..ade135008e98af8a7565675b4ad5c6ecd3804fb7 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -286,11 +286,16 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                plane = to_rcar_plane(state->planes[i]);
                plane_state = to_rcar_plane_state(state->plane_states[i]);
 
+               dev_dbg(rcdu->dev, "%s: checking plane (%u,%u)\n", __func__,
+                       plane->group->index, plane - plane->group->planes);
+
                /* If the plane is being disabled we don't need to go through
                 * the full reallocation procedure. Just mark the hardware
                 * plane(s) as freed.
                 */
                if (!plane_state->format) {
+                       dev_dbg(rcdu->dev, "%s: plane is being disabled\n",
+                               __func__);
                        index = plane - plane->group->planes;
                        group_freed_planes[plane->group->index] |= 1 << index;
                        plane_state->hwindex = -1;
@@ -301,6 +306,8 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                 * mark the hardware plane(s) as free.
                 */
                if (rcar_du_plane_needs_realloc(plane, plane_state)) {
+                       dev_dbg(rcdu->dev, "%s: plane needs reallocation\n",
+                               __func__);
                        groups |= 1 << plane->group->index;
                        needs_realloc = true;
 
@@ -326,6 +333,9 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                struct rcar_du_group *group = &rcdu->groups[index];
                unsigned int used_planes = 0;
 
+               dev_dbg(rcdu->dev, "%s: finding free planes for group %u\n",
+                       __func__, index);
+
                for (i = 0; i < RCAR_DU_NUM_KMS_PLANES; ++i) {
                        struct rcar_du_plane *plane = &group->planes[i];
                        struct rcar_du_plane_state *plane_state;
@@ -342,15 +352,31 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                         * above. Use the local freed planes list to check for
                         * that condition instead.
                         */
-                       if (group_freed_planes[index] & (1 << i))
+                       if (group_freed_planes[index] & (1 << i)) {
+                               dev_dbg(rcdu->dev,
+                                       "%s: plane (%u,%u) has been freed, skipping\n",
+                                       __func__, plane->group->index,
+                                       plane - plane->group->planes);
                                continue;
+                       }
 
                        plane_state = to_rcar_plane_state(plane->plane.state);
                        used_planes |= rcar_du_plane_hwmask(plane_state);
+
+                       dev_dbg(rcdu->dev,
+                               "%s: plane (%u,%u) uses %u hwplanes (index %d)\n",
+                               __func__, plane->group->index,
+                               plane - plane->group->planes,
+                               plane_state->format ?
+                               plane_state->format->planes : 0,
+                               plane_state->hwindex);
                }
 
                group_free_planes[index] = 0xff & ~used_planes;
                groups &= ~(1 << index);
+
+               dev_dbg(rcdu->dev, "%s: group %u free planes mask 0x%02x\n",
+                       __func__, index, group_free_planes[index]);
        }
 
        /* Reallocate hardware planes for each plane that needs it. */
@@ -365,6 +391,9 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                plane = to_rcar_plane(state->planes[i]);
                plane_state = to_rcar_plane_state(state->plane_states[i]);
 
+               dev_dbg(rcdu->dev, "%s: allocating plane (%u,%u)\n", __func__,
+                       plane->group->index, plane - plane->group->planes);
+
                /* Skip planes that are being disabled or don't need to be
                 * reallocated.
                 */
@@ -380,10 +409,17 @@ static int rcar_du_atomic_check(struct drm_device *dev,
                        return idx;
                }
 
+               dev_dbg(rcdu->dev, "%s: allocated %u hwplanes (index %u)\n",
+                       __func__, plane_state->format->planes, idx);
+
                plane_state->hwindex = idx;
 
                group_free_planes[plane->group->index] &=
                        ~rcar_du_plane_hwmask(plane_state);
+
+               dev_dbg(rcdu->dev, "%s: group %u free planes mask 0x%02x\n",
+                       __func__, plane->group->index,
+                       group_free_planes[plane->group->index]);
        }
 
        return 0;