drm/msm/mdp5: Create only as many CRTCs as we need

We currently create CRTCs equaling to the # of Layer Mixer blocks we
have on the MDP5 HW. This number is generally more than the # of encoders
(INTFs) we have in the MDSS HW. The number of encoders connected to
displays on the platform (as described by DT) would be even lesser.

Create only N drm_crtcs, where N is the number of drm_encoders
successfully registered. To do this, we call modeset_init_intf() before
we init the drm_crtcs and drm_planes.

Because of this change, setting encoder->possible_crtcs needs to be moved
from construct_encoder() to a later point when we know how many CRTCs we
have.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index 9794cad..ecfa389 100644 (file)
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -293,7 +293,6 @@ static struct drm_encoder *construct_encoder(struct mdp5_kms *mdp5_kms,
                return encoder;
        }
 
-       encoder->possible_crtcs = (1 << priv->num_crtcs) - 1;
        priv->encoders[priv->num_encoders++] = encoder;
 
        return encoder;
@@ -411,16 +410,35 @@ static int modeset_init(struct mdp5_kms *mdp5_kms)
        struct drm_device *dev = mdp5_kms->dev;
        struct msm_drm_private *priv = dev->dev_private;
        const struct mdp5_cfg_hw *hw_cfg;
+       unsigned int num_crtcs;
        int i, ret;
 
        hw_cfg = mdp5_cfg_get_hw_config(mdp5_kms->cfg);
 
-       /* Construct planes equaling the number of hw pipes, and CRTCs
-        * for the N layer-mixers (LM).  The first N planes become primary
+       /*
+        * Construct encoders and modeset initialize connector devices
+        * for each external display interface.
+        */
+       for (i = 0; i < ARRAY_SIZE(hw_cfg->intf.connect); i++) {
+               ret = modeset_init_intf(mdp5_kms, i);
+               if (ret)
+                       goto fail;
+       }
+
+       /*
+        * We should ideally have less number of encoders (set up by parsing
+        * the MDP5 interfaces) than the number of layer mixers present in HW,
+        * but let's be safe here anyway
+        */
+       num_crtcs = min(priv->num_encoders, mdp5_cfg->lm.count);
+
+       /*
+        * Construct planes equaling the number of hw pipes, and CRTCs for the
+        * N encoders set up by the driver. The first N planes become primary
         * planes for the CRTCs, with the remainder as overlay planes:
         */
        for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
-               bool primary = i < mdp5_cfg->lm.count;
+               bool primary = i < num_crtcs;
                struct drm_plane *plane;
                struct drm_crtc *crtc;
 
@@ -444,13 +462,14 @@ static int modeset_init(struct mdp5_kms *mdp5_kms)
                priv->crtcs[priv->num_crtcs++] = crtc;
        }
 
-       /* Construct encoders and modeset initialize connector devices
-        * for each external display interface.
+       /*
+        * Now that we know the number of crtcs we've created, set the possible
+        * crtcs for the encoders
         */
-       for (i = 0; i < ARRAY_SIZE(hw_cfg->intf.connect); i++) {
-               ret = modeset_init_intf(mdp5_kms, i);
-               if (ret)
-                       goto fail;
+       for (i = 0; i < priv->num_encoders; i++) {
+               struct drm_encoder *encoder = priv->encoders[i];
+
+               encoder->possible_crtcs = (1 << priv->num_crtcs) - 1;
        }
 
        return 0;