For DSI, we want to pre_enable once the DSI link is up but before
video packets are being sent, and similarly we want to be able to
post_disable while the link is still up but after video has stopped.
Given that with drm_panels we've had issues with drivers missing calls
to one of the hooks, include some checks in the atomic helpers that
the driver got it right.
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/gpu/drm/drm_atomic_helper.c | 32 +++++++++++++++++++++++++----
drivers/gpu/drm/drm_bridge.c | 12 +++++++++++
include/drm/drm_bridge.h | 21 +++++++++++++++++++
3 files changed, 61 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 130da5195f3b..2950ddcc9013 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -950,7 +950,13 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
* Each encoder has at most one connector (since we always steal
* it away), so we won't call disable hooks twice.
*/
- drm_bridge_disable(encoder->bridge);
+ if (encoder->bridge) {
+ encoder->bridge->post_disable_called = false;
+ encoder->bridge->disable_called = false;
+
+ if (!encoder->bridge->disable_midlayer_calls)
+ drm_bridge_disable(encoder->bridge);
+ }
/* Right function depends upon target state. */
if (funcs) {
@@ -962,7 +968,13 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
}
- drm_bridge_post_disable(encoder->bridge);
+ if (encoder->bridge) {
+ if (!encoder->bridge->disable_midlayer_calls)
+ drm_bridge_post_disable(encoder->bridge);
+
+ WARN_ON(!encoder->bridge->post_disable_called);
+ WARN_ON(!encoder->bridge->disable_called);
+ }
}
for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
@@ -1240,7 +1252,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
* Each encoder has at most one connector (since we always steal
* it away), so we won't call enable hooks twice.
*/
- drm_bridge_pre_enable(encoder->bridge);
+ if (encoder->bridge) {
+ encoder->bridge->pre_enable_called = false;
+ encoder->bridge->enable_called = false;
+
+ if (!encoder->bridge->disable_midlayer_calls)
+ drm_bridge_pre_enable(encoder->bridge);
+ }
if (funcs) {
if (funcs->enable)
@@ -1249,7 +1267,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
funcs->commit(encoder);
}
- drm_bridge_enable(encoder->bridge);
+ if (encoder->bridge) {
+ if (!encoder->bridge->disable_midlayer_calls)
+ drm_bridge_enable(encoder->bridge);
+
+ WARN_ON(!encoder->bridge->pre_enable_called);
+ WARN_ON(!encoder->bridge->enable_called);
+ }
}
}
EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 1638bfe9627c..847c4209da60 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -153,6 +153,8 @@ void drm_bridge_detach(struct drm_bridge *bridge)
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
+ bridge->disable_midlayer_calls = false;
+
bridge->dev = NULL;
}
@@ -248,6 +250,8 @@ void drm_bridge_disable(struct drm_bridge *bridge)
if (!bridge)
return;
+ bridge->disable_called = true;
+
drm_bridge_disable(bridge->next);
if (bridge->funcs->disable)
@@ -270,6 +274,9 @@ void drm_bridge_post_disable(struct drm_bridge *bridge)
if (!bridge)
return;
+ WARN_ON(!bridge->disable_called);
+ bridge->post_disable_called = true;
+
if (bridge->funcs->post_disable)
bridge->funcs->post_disable(bridge);
@@ -319,6 +326,8 @@ void drm_bridge_pre_enable(struct drm_bridge *bridge)
if (!bridge)
return;
+ bridge->pre_enable_called = true;
+
drm_bridge_pre_enable(bridge->next);
if (bridge->funcs->pre_enable)
@@ -341,6 +350,9 @@ void drm_bridge_enable(struct drm_bridge *bridge)
if (!bridge)
return;
+ WARN_ON(!bridge->pre_enable_called);
+ bridge->enable_called = true;
+
if (bridge->funcs->enable)
bridge->funcs->enable(bridge);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index bd850747ce54..ba0a227c96b7 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -294,6 +294,27 @@ struct drm_bridge {
const struct drm_bridge_funcs *funcs;
/** @driver_private: pointer to the bridge driver's internal context */
void *driver_private;
+
+ /**
+ * @disable_midlayer_calls:
+ *
+ * disables the calls from the DRM atomic helpers into the
+ * bridge, leaving them to be performed by the driver. This
+ * may be useful for encoders such as DSI, where the
+ * pre_enable/post_disable hooks want to be called while the
+ * bus is still enabled but before/after video packets are
+ * being sent.
+ */
+ bool disable_midlayer_calls : 1;
+
+ /* private: flags for atomic helpers to check that the driver
+ * called the bridge functions properly if
+ * @disable_midlayer_calls was set.
+ */
+ bool pre_enable_called : 1;
+ bool enable_called : 1;
+ bool disable_called : 1;
+ bool post_disable_called : 1;
};
void drm_bridge_add(struct drm_bridge *bridge);
--
2.17.0
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