drm/atomic: Introduce helper to lookup connector by encoder

With the bridges switching over to drm_bridge_connector, the direct
association between a bridge driver and its connector was lost.

This is mitigated for atomic bridge drivers by the fact you can access
the encoder, and then call drm_atomic_get_old_connector_for_encoder() or
drm_atomic_get_new_connector_for_encoder() with drm_atomic_state.

This was also made easier by providing drm_atomic_state directly to all
atomic hooks bridges can implement.

However, bridge drivers don't have a way to access drm_atomic_state
outside of the modeset path, like from the hotplug interrupt path or any
interrupt handler.

Let's introduce a function to retrieve the connector currently assigned
to an encoder, without using drm_atomic_state, to make these drivers'
life easier.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Tested-by: Herve Codina <herve.codina@bootlin.com>
Co-developed-by: Simona Vetter <simona.vetter@intel.com>
Signed-off-by: Simona Vetter <simona.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313-bridge-connector-v6-4-511c54a604fb@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
This commit is contained in:
Maxime Ripard
2025-03-13 12:59:58 +01:00
parent 6b4dc0803a
commit a7e4886e06
2 changed files with 62 additions and 0 deletions

View File

@@ -933,6 +933,9 @@ EXPORT_SYMBOL(drm_atomic_get_new_private_obj_state);
* state). This is especially true in enable hooks because the pipeline has
* changed.
*
* If you don't have access to the atomic state, see
* drm_atomic_get_connector_for_encoder().
*
* Returns: The old connector connected to @encoder, or NULL if the encoder is
* not connected.
*/
@@ -967,6 +970,9 @@ EXPORT_SYMBOL(drm_atomic_get_old_connector_for_encoder);
* attached to @encoder vs ones that do (and to inspect their state). This is
* especially true in disable hooks because the pipeline will change.
*
* If you don't have access to the atomic state, see
* drm_atomic_get_connector_for_encoder().
*
* Returns: The new connector connected to @encoder, or NULL if the encoder is
* not connected.
*/
@@ -987,6 +993,59 @@ drm_atomic_get_new_connector_for_encoder(const struct drm_atomic_state *state,
}
EXPORT_SYMBOL(drm_atomic_get_new_connector_for_encoder);
/**
* drm_atomic_get_connector_for_encoder - Get connector currently assigned to an encoder
* @encoder: The encoder to find the connector of
* @ctx: Modeset locking context
*
* This function finds and returns the connector currently assigned to
* an @encoder.
*
* It is similar to the drm_atomic_get_old_connector_for_encoder() and
* drm_atomic_get_new_connector_for_encoder() helpers, but doesn't
* require access to the atomic state. If you have access to it, prefer
* using these. This helper is typically useful in situations where you
* don't have access to the atomic state, like detect, link repair,
* threaded interrupt handlers, or hooks from other frameworks (ALSA,
* CEC, etc.).
*
* Returns:
* The connector connected to @encoder, or an error pointer otherwise.
* When the error is EDEADLK, a deadlock has been detected and the
* sequence must be restarted.
*/
struct drm_connector *
drm_atomic_get_connector_for_encoder(const struct drm_encoder *encoder,
struct drm_modeset_acquire_ctx *ctx)
{
struct drm_connector_list_iter conn_iter;
struct drm_connector *out_connector = ERR_PTR(-EINVAL);
struct drm_connector *connector;
struct drm_device *dev = encoder->dev;
int ret;
ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
if (ret)
return ERR_PTR(ret);
drm_connector_list_iter_begin(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
if (!connector->state)
continue;
if (encoder == connector->state->best_encoder) {
out_connector = connector;
break;
}
}
drm_connector_list_iter_end(&conn_iter);
drm_modeset_unlock(&dev->mode_config.connection_mutex);
return out_connector;
}
EXPORT_SYMBOL(drm_atomic_get_connector_for_encoder);
/**
* drm_atomic_get_old_crtc_for_encoder - Get old crtc for an encoder
* @state: Atomic state