[PATCH v4 07/15] drm/bridge: Add helper to reset bridge pipeline
Maxime Ripard
mripard at kernel.org
Tue Feb 25 16:43:55 UTC 2025
Let's provide an helper to make it easier for bridge drivers to
power-cycle their bridge.
Co-developed-by: Simona Vetter <simona.vetter at ffwll.ch>
Signed-off-by: Maxime Ripard <mripard at kernel.org>
---
drivers/gpu/drm/drm_bridge.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
include/drm/drm_bridge.h | 2 ++
2 files changed, 46 insertions(+)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 8241c00e4506eceeb9bb4ba74a38d8f360c65d38..ca894531a2042fc9296c40a1f51a6cdea6e97ed7 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -24,10 +24,11 @@
#include <linux/err.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_edid.h>
#include <drm/drm_encoder.h>
@@ -1269,10 +1270,53 @@ void drm_bridge_hpd_notify(struct drm_bridge *bridge,
bridge->hpd_cb(bridge->hpd_data, status);
mutex_unlock(&bridge->hpd_mutex);
}
EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify);
+/**
+ * drm_bridge_reset_crtc - Reset the pipeline feeding a bridge
+ * @bridge: DRM bridge to reset
+ * @ctx: lock acquisition context
+ *
+ * Reset a @bridge pipeline. It will power-cycle all active components
+ * between the CRTC and connector that bridge is connected to.
+ *
+ * Returns:
+ *
+ * 0 on success or a negative error code on failure. If the error
+ * returned is EDEADLK, the whole atomic sequence must be restarted.
+ */
+int drm_bridge_reset_crtc(struct drm_bridge *bridge,
+ struct drm_modeset_acquire_ctx *ctx)
+{
+ struct drm_connector *connector;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_device *dev = encoder->dev;
+ struct drm_crtc *crtc;
+ int ret;
+
+ ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
+ if (ret)
+ return ret;
+
+ connector = drm_atomic_get_connector_for_encoder(encoder, ctx);
+ if (IS_ERR(connector)) {
+ ret = PTR_ERR(connector);
+ goto out;
+ }
+
+ crtc = connector->state->crtc;
+ ret = drm_atomic_helper_reset_crtc(crtc, ctx);
+ if (ret)
+ goto out;
+
+out:
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+ return ret;
+}
+EXPORT_SYMBOL(drm_bridge_reset_crtc);
+
#ifdef CONFIG_OF
/**
* of_drm_find_bridge - find the bridge corresponding to the device node in
* the global bridge list
*
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 6fb1da7c195e99143a67a999d16fe361c1e3f4ab..32169e62463bb268a281a5903c0c9f448a1042b3 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -1085,10 +1085,12 @@ void drm_bridge_hpd_enable(struct drm_bridge *bridge,
enum drm_connector_status status),
void *data);
void drm_bridge_hpd_disable(struct drm_bridge *bridge);
void drm_bridge_hpd_notify(struct drm_bridge *bridge,
enum drm_connector_status status);
+int drm_bridge_reset_crtc(struct drm_bridge *bridge,
+ struct drm_modeset_acquire_ctx *ctx);
#ifdef CONFIG_DRM_PANEL_BRIDGE
bool drm_bridge_is_panel(const struct drm_bridge *bridge);
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
--
2.48.1
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