[PATCH RFC 2/9] drm/bridge: add atomic_print_state callback

[Dmitry Baryshkov]

Bridge drivers can subclass drm_bridge_state, but the state is printed
by the bridge core, which only knows about the bus configuration. The
driver-specific part of the state is thus missing from the state dumps,
making it hard to debug such drivers.

Add an optional atomic_print_state callback letting bridge drivers print
the rest of their state.

Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/drm_bridge.c | 3 +++
 include/drm/drm_bridge.h     | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 0f37e3ade016..2b06171b122a 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -571,6 +571,9 @@ drm_bridge_atomic_print_priv_state(struct drm_printer *p,
 	drm_printf_indent(p, 1, "output bus configuration:\n");
 	drm_printf_indent(p, 2, "code: %04x\n", state->output_bus_cfg.format);
 	drm_printf_indent(p, 2, "flags: %08x\n", state->output_bus_cfg.flags);
+
+	if (bridge->funcs->atomic_print_state)
+		bridge->funcs->atomic_print_state(p, state);
 }
 
 static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 1981d24a700d..8b0c72d93d9b 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -312,6 +312,15 @@ struct drm_bridge_funcs {
 	void (*atomic_destroy_state)(struct drm_bridge *bridge,
 				     struct drm_bridge_state *state);
 
+	/**
+	 * @atomic_print_state:
+	 *
+	 * If driver subclasses &struct drm_bridge_state, it should implement
+	 * this optional hook for printing additional driver specific state.
+	 */
+	void (*atomic_print_state)(struct drm_printer *p,
+				   const struct drm_bridge_state *state);
+
 	/**
 	 * @atomic_get_output_bus_fmts:
 	 *

-- 
2.47.3