[PATCH v2 10/21] drm/bridge: Make the bridge chain a double-linked list
Boris Brezillon
boris.brezillon at collabora.com
Mon Aug 26 15:26:38 UTC 2019
So that each element in the chain can easily access its predecessor.
This will be needed to support bus format negotiation between elements
of the bridge chain.
Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
---
Changes in v2:
* Adjust things to the "dummy encoder bridge" change (patch 2 in this
series)
---
drivers/gpu/drm/drm_bridge.c | 177 ++++++++++++++++++----------------
drivers/gpu/drm/drm_encoder.c | 6 +-
include/drm/drm_bridge.h | 4 +-
include/drm/drm_encoder.h | 7 ++
4 files changed, 107 insertions(+), 87 deletions(-)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 3d9a6c6a7d4e..695ad67d33a5 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -55,7 +55,7 @@
* just provide additional hooks to get the desired output at the end of the
* encoder chain.
*
- * Bridges can also be chained up using the &drm_bridge.next pointer.
+ * Bridges can also be chained up using the &drm_bridge.chain_node field.
*
* Both legacy CRTC helpers and the new atomic modeset helpers support bridges.
*/
@@ -114,6 +114,7 @@ EXPORT_SYMBOL(drm_bridge_remove);
int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
struct drm_bridge *previous)
{
+ LIST_HEAD(tmp_list);
int ret;
if (!encoder || !bridge)
@@ -127,6 +128,7 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
bridge->dev = encoder->dev;
bridge->encoder = encoder;
+ list_add_tail(&bridge->chain_node, &tmp_list);
if (bridge->funcs->attach) {
ret = bridge->funcs->attach(bridge);
@@ -137,10 +139,12 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
}
}
- if (previous)
- previous->next = bridge;
- else if (bridge != &encoder->bridge)
- encoder->bridge.next = bridge;
+ if (bridge == &encoder->bridge)
+ list_splice(&tmp_list, &encoder->bridge_chain);
+ else if (!previous)
+ list_splice(&tmp_list, &encoder->bridge.chain_node);
+ else
+ list_splice(&tmp_list, &previous->chain_node);
return 0;
}
@@ -157,6 +161,7 @@ void drm_bridge_detach(struct drm_bridge *bridge)
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
+ list_del(&bridge->chain_node);
bridge->dev = NULL;
}
@@ -170,7 +175,10 @@ void drm_bridge_detach(struct drm_bridge *bridge)
struct drm_bridge *
drm_bridge_chain_get_next_bridge(struct drm_bridge *bridge)
{
- return bridge->next;
+ if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
+ return NULL;
+
+ return list_next_entry(bridge, chain_node);
}
EXPORT_SYMBOL(drm_bridge_chain_get_next_bridge);
@@ -204,18 +212,17 @@ bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode)
{
- bool ret = true;
+ struct drm_encoder *encoder = bridge->encoder;
- if (!bridge)
- return true;
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (!bridge->funcs->mode_fixup)
+ continue;
- if (bridge->funcs->mode_fixup)
- ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode);
+ if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))
+ return false;
+ }
- ret = ret && drm_bridge_chain_mode_fixup(bridge->next, mode,
- adjusted_mode);
-
- return ret;
+ return true;
}
EXPORT_SYMBOL(drm_bridge_chain_mode_fixup);
@@ -238,18 +245,20 @@ enum drm_mode_status
drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
const struct drm_display_mode *mode)
{
- enum drm_mode_status ret = MODE_OK;
+ struct drm_encoder *encoder = bridge->encoder;
- if (!bridge)
- return ret;
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ enum drm_mode_status ret;
+
+ if (!bridge->funcs->mode_valid)
+ continue;
- if (bridge->funcs->mode_valid)
ret = bridge->funcs->mode_valid(bridge, mode);
+ if (ret != MODE_OK)
+ return ret;
+ }
- if (ret != MODE_OK)
- return ret;
-
- return drm_bridge_chain_mode_valid(bridge->next, mode);
+ return MODE_OK;
}
EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
@@ -265,13 +274,16 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
*/
void drm_bridge_chain_disable(struct drm_bridge *bridge)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_bridge *iter;
- drm_bridge_chain_disable(bridge->next);
+ list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
+ if (iter->funcs->disable)
+ iter->funcs->disable(iter);
- if (bridge->funcs->disable)
- bridge->funcs->disable(bridge);
+ if (iter == bridge)
+ break;
+ }
}
EXPORT_SYMBOL(drm_bridge_chain_disable);
@@ -288,13 +300,12 @@ EXPORT_SYMBOL(drm_bridge_chain_disable);
*/
void drm_bridge_chain_post_disable(struct drm_bridge *bridge)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
- if (bridge->funcs->post_disable)
- bridge->funcs->post_disable(bridge);
-
- drm_bridge_chain_post_disable(bridge->next);
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (bridge->funcs->post_disable)
+ bridge->funcs->post_disable(bridge);
+ }
}
EXPORT_SYMBOL(drm_bridge_chain_post_disable);
@@ -314,13 +325,12 @@ void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
const struct drm_display_mode *adjusted_mode)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
- if (bridge->funcs->mode_set)
- bridge->funcs->mode_set(bridge, mode, adjusted_mode);
-
- drm_bridge_chain_mode_set(bridge->next, mode, adjusted_mode);
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (bridge->funcs->mode_set)
+ bridge->funcs->mode_set(bridge, mode, adjusted_mode);
+ }
}
EXPORT_SYMBOL(drm_bridge_chain_mode_set);
@@ -337,13 +347,13 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_set);
*/
void drm_bridge_chain_pre_enable(struct drm_bridge *bridge)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_bridge *iter;
- drm_bridge_chain_pre_enable(bridge->next);
-
- if (bridge->funcs->pre_enable)
- bridge->funcs->pre_enable(bridge);
+ list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
+ if (iter->funcs->pre_enable)
+ iter->funcs->pre_enable(iter);
+ }
}
EXPORT_SYMBOL(drm_bridge_chain_pre_enable);
@@ -359,13 +369,12 @@ EXPORT_SYMBOL(drm_bridge_chain_pre_enable);
*/
void drm_bridge_chain_enable(struct drm_bridge *bridge)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
- if (bridge->funcs->enable)
- bridge->funcs->enable(bridge);
-
- drm_bridge_chain_enable(bridge->next);
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (bridge->funcs->enable)
+ bridge->funcs->enable(bridge);
+ }
}
EXPORT_SYMBOL(drm_bridge_chain_enable);
@@ -384,15 +393,18 @@ EXPORT_SYMBOL(drm_bridge_chain_enable);
void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_bridge *iter;
- drm_atomic_bridge_chain_disable(bridge->next, state);
+ list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
+ if (iter->funcs->atomic_disable)
+ iter->funcs->atomic_disable(iter, state);
+ else if (iter->funcs->disable)
+ iter->funcs->disable(iter);
- if (bridge->funcs->atomic_disable)
- bridge->funcs->atomic_disable(bridge, state);
- else if (bridge->funcs->disable)
- bridge->funcs->disable(bridge);
+ if (iter == bridge)
+ break;
+ }
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
@@ -412,15 +424,14 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
- if (bridge->funcs->atomic_post_disable)
- bridge->funcs->atomic_post_disable(bridge, state);
- else if (bridge->funcs->post_disable)
- bridge->funcs->post_disable(bridge);
-
- drm_atomic_bridge_chain_post_disable(bridge->next, state);
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (bridge->funcs->atomic_post_disable)
+ bridge->funcs->atomic_post_disable(bridge, state);
+ else if (bridge->funcs->post_disable)
+ bridge->funcs->post_disable(bridge);
+ }
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
@@ -440,15 +451,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_bridge *iter;
- drm_atomic_bridge_chain_pre_enable(bridge->next, state);
+ list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
+ if (iter->funcs->atomic_pre_enable)
+ iter->funcs->atomic_pre_enable(iter, state);
+ else if (iter->funcs->pre_enable)
+ iter->funcs->pre_enable(iter);
- if (bridge->funcs->atomic_pre_enable)
- bridge->funcs->atomic_pre_enable(bridge, state);
- else if (bridge->funcs->pre_enable)
- bridge->funcs->pre_enable(bridge);
+ if (iter == bridge)
+ break;
+ }
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
@@ -467,15 +481,14 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
- if (!bridge)
- return;
+ struct drm_encoder *encoder = bridge->encoder;
- if (bridge->funcs->atomic_enable)
- bridge->funcs->atomic_enable(bridge, state);
- else if (bridge->funcs->enable)
- bridge->funcs->enable(bridge);
-
- drm_atomic_bridge_chain_enable(bridge->next, state);
+ list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
+ if (bridge->funcs->atomic_enable)
+ bridge->funcs->atomic_enable(bridge, state);
+ else if (bridge->funcs->enable)
+ bridge->funcs->enable(bridge);
+ }
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
index 686053bf41b9..9bf642c09c55 100644
--- a/drivers/gpu/drm/drm_encoder.c
+++ b/drivers/gpu/drm/drm_encoder.c
@@ -143,6 +143,7 @@ int drm_encoder_init(struct drm_device *dev,
goto out_put;
}
+ INIT_LIST_HEAD(&encoder->bridge_chain);
if (!encoder->bridge.funcs)
encoder->bridge.funcs = &dummy_bridge_funcs;
@@ -177,10 +178,9 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
* the indices on the drm_encoder after us in the encoder_list.
*/
- for (bridge = &encoder->bridge; bridge; bridge = next) {
- next = bridge->next;
+ list_for_each_entry_safe(bridge, next, &encoder->bridge_chain,
+ chain_node)
drm_bridge_detach(bridge);
- }
drm_mode_object_unregister(dev, &encoder->base);
kfree(encoder->name);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 7809fca99b2d..8af92f0a9541 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -383,8 +383,8 @@ struct drm_bridge {
struct drm_device *dev;
/** @encoder: encoder to which this bridge is connected */
struct drm_encoder *encoder;
- /** @next: the next bridge in the encoder chain */
- struct drm_bridge *next;
+ /** @chain_node: used to form a bridge chain */
+ struct list_head chain_node;
#ifdef CONFIG_OF
/** @of_node: device node pointer to the bridge */
struct device_node *of_node;
diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
index 30d347c37402..b3374d045801 100644
--- a/include/drm/drm_encoder.h
+++ b/include/drm/drm_encoder.h
@@ -173,6 +173,13 @@ struct drm_encoder {
*/
struct drm_crtc *crtc;
+ /**
+ * @bridge_chain: Bridges attached to this encoder. The first entry of
+ * this list is always &drm_encoder.bridge. It may be followed by other
+ * bridge entities.
+ */
+ struct list_head bridge_chain;
+
/**
* @bridge: Bridge representing our encoder. Other bridges might be
* linked to this dummy bridge element to form an encoder chain.
--
2.21.0
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