drm/atomic-helper: Add an atomice best_encoder callback

With legacy helpers all the routing was already set up when calling
best_encoder and so could be inspected. But with atomic it's staged,
hence we need a new atomic compliant callback for drivers which need
to inspect the requested state and can't just decided the best encoder
statically.

This is needed to fix up i915 dp mst where we need to pick the right
encoder depending upon the requested CRTC for the connector.

v2: Don't forget to amend the kerneldoc

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index aac212297b49fb1953dab1749f23dcd77977bcb7..8694ca9beee35de502dd35a17ec7858682294097 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -196,7 +196,12 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
        }
 
        funcs = connector->helper_private;
-       new_encoder = funcs->best_encoder(connector);
+
+       if (funcs->atomic_best_encoder)
+               new_encoder = funcs->atomic_best_encoder(connector,
+                                                        connector_state);
+       else
+               new_encoder = funcs->best_encoder(connector);
 
        if (!new_encoder) {
                DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n",

diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
index c8fc187061de5fbd9fc8545f602a62baaa45b8cc..918aa68b5199d54501a2a9d68404e44388e9e04e 100644 (file)
--- a/include/drm/drm_crtc_helper.h
+++ b/include/drm/drm_crtc_helper.h
@@ -168,6 +168,7 @@ struct drm_encoder_helper_funcs {
  * @get_modes: get mode list for this connector
  * @mode_valid: is this mode valid on the given connector? (optional)
  * @best_encoder: return the preferred encoder for this connector
+ * @atomic_best_encoder: atomic version of @best_encoder
  *
  * The helper operations are called by the mid-layer CRTC helper.
  */
@@ -176,6 +177,8 @@ struct drm_connector_helper_funcs {
        enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
                                           struct drm_display_mode *mode);
        struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
+       struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
+                                                  struct drm_connector_state *connector_state);
 };
 
 extern void drm_helper_disable_unused_functions(struct drm_device *dev);