Hi Boris,
Thank you for the patch.
On Wed, Oct 23, 2019 at 05:45:03PM +0200, Boris Brezillon wrote:
So that bridge drivers have a way to check/reject an atomic operation. The drm_atomic_bridge_chain_check() (which is just a wrapper around the ->atomic_check() hook) is called in place of drm_bridge_chain_mode_fixup() (when ->atomic_check() is not implemented, the core falls back on ->mode_fixup(), so the behavior should stay the same for existing bridge drivers).
Signed-off-by: Boris Brezillon boris.brezillon@collabora.com
Changes in v3:
- None
Changes in v2:
- Clarify the fact that ->atomic_check() is replacing ->mode_fixup()
drivers/gpu/drm/drm_atomic_helper.c | 12 +++--- drivers/gpu/drm/drm_bridge.c | 62 +++++++++++++++++++++++++++++ include/drm/drm_bridge.h | 29 +++++++++++++- 3 files changed, 96 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index de985ba7ce2d..1d0a19511a0d 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -437,12 +437,12 @@ mode_fixup(struct drm_atomic_state *state) funcs = encoder->helper_private;
bridge = drm_bridge_chain_get_first_bridge(encoder);
ret = drm_bridge_chain_mode_fixup(bridge,&new_crtc_state->mode,&new_crtc_state->adjusted_mode);if (!ret) {DRM_DEBUG_ATOMIC("Bridge fixup failed\n");return -EINVAL;
ret = drm_atomic_bridge_chain_check(bridge,new_crtc_state,new_conn_state);if (ret) {DRM_DEBUG_ATOMIC("Bridge atomic check failed\n");return ret;}
if (funcs && funcs->atomic_check) {
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 377866e3214f..990e056296bd 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -615,6 +615,68 @@ void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge, } EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
+static int drm_atomic_bridge_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,struct drm_connector_state *conn_state)+{
- if (bridge->funcs->atomic_check) {
struct drm_bridge_state *bridge_state;int ret;bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,bridge);if (WARN_ON(!bridge_state))return -EINVAL;ret = bridge->funcs->atomic_check(bridge, bridge_state,crtc_state, conn_state);if (ret)return ret;- } else if (bridge->funcs->mode_fixup) {
if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,&crtc_state->adjusted_mode))return -EINVAL;- }
- return 0;
+}
+/**
- drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
- @bridge: bridge control structure
- @crtc_state: new CRTC state
- @conn_state: new connector state
- Calls &drm_bridge_funcs.atomic_check() (falls back on
- &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
- starting from the last bridge to the first. These are called before calling
- &drm_encoder_helper_funcs.atomic_check()
- RETURNS:
- 0 on success, a negative error code on failure
- */
+int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,struct drm_connector_state *conn_state)+{
- struct drm_encoder *encoder = bridge->encoder;
- struct drm_bridge *iter;
- list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
int ret;ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);if (ret)return ret;if (iter == bridge)break;- }
- return 0;
+} +EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
/**
- drm_atomic_helper_bridge_destroy_state() - Default destroy state helper
- @bridge: the bridge this state refers to
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index b1f557d8dba9..2beb1ef9a733 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -127,7 +127,9 @@ struct drm_bridge_funcs { * this function passes all other callbacks must succeed for this * configuration. *
* The @mode_fixup callback is optional.
* The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()* is not called when &drm_bridge_funcs.atomic_check() is implemented,* so only one of them should be provided.
- NOTE:
@@ -391,6 +393,28 @@ struct drm_bridge_funcs { void (*atomic_destroy_state)(struct drm_bridge *bridge, struct drm_bridge_state *state);
- /**
* @atomic_check:** This method is responsible for checking bridge state correctness.* It can also check the state of the surrounding components in chain* to make sure the whole pipeline can work properly.
As explained in the review of the RFC, I think it's a mistake not to define the semantics of this operation precisely, and in particular not to define explictly what parameters bridge drivers are allowed to modify here. I however don't want to make this a prerequisite for your series, so
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
but I'm sure we'll regret this later when different bridges will have slightly incompatible implementations.
** &drm_bridge_funcs.atomic_check() hooks are called in reverse* order (from the last to the first bridge).** This method is optional. &drm_bridge_funcs.mode_fixup() is not* called when &drm_bridge_funcs.atomic_check() is implemented, so only* one of them should be provided.** RETURNS:* zero if the check passed, a negative error code otherwise.*/- int (*atomic_check)(struct drm_bridge *bridge,
struct drm_bridge_state *bridge_state,struct drm_crtc_state *crtc_state,struct drm_connector_state *conn_state);- /**
- @atomic_reset:
@@ -542,6 +566,9 @@ void drm_bridge_chain_mode_set(struct drm_bridge *bridge, void drm_bridge_chain_pre_enable(struct drm_bridge *bridge); void drm_bridge_chain_enable(struct drm_bridge *bridge);
+int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,struct drm_connector_state *conn_state);void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge, struct drm_atomic_state *state); void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,