drm: allow drm_atomic_print_state() to accept any drm_printer

Currently drm_atomic_print_state() internally allocates and uses a
drm_info printer. Allow it to accept any drm_printer type so that
the API can be leveraged even for taking drm snapshot.

Rename the drm_atomic_print_state() to drm_atomic_print_new_state()
so that it reflects its functionality better.

changes in v5:
- none

Reported-by: kernel test robot <[e-mail]>
Signed-off-by: Abhinav Kumar <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/drm_atomic.c

···
 /*
  * Copyright (C) 2014 Red Hat
  * Copyright (C) 2014 Intel Corp.
+ * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
···
 }
 EXPORT_SYMBOL(__drm_atomic_helper_set_config);
 
-void drm_atomic_print_state(const struct drm_atomic_state *state)
+/**
+ * drm_atomic_print_new_state - prints drm atomic state
+ * @state: atomic configuration to check
+ * @p: drm printer
+ *
+ * This functions prints the drm atomic state snapshot using the drm printer
+ * which is passed to it. This snapshot can be used for debugging purposes.
+ *
+ * Note that this function looks into the new state objects and hence its not
+ * safe to be used after the call to drm_atomic_helper_commit_hw_done().
+ */
+void drm_atomic_print_new_state(const struct drm_atomic_state *state,
+		struct drm_printer *p)
 {
-	struct drm_printer p = drm_info_printer(state->dev->dev);
 	struct drm_plane *plane;
 	struct drm_plane_state *plane_state;
 	struct drm_crtc *crtc;
···
 	struct drm_connector_state *connector_state;
 	int i;
 
+	if (!p) {
+		DRM_ERROR("invalid drm printer\n");
+		return;
+	}
+
 	DRM_DEBUG_ATOMIC("checking %p\n", state);
 
 	for_each_new_plane_in_state(state, plane, plane_state, i)
-		drm_atomic_plane_print_state(&p, plane_state);
+		drm_atomic_plane_print_state(p, plane_state);
 
 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
-		drm_atomic_crtc_print_state(&p, crtc_state);
+		drm_atomic_crtc_print_state(p, crtc_state);
 
 	for_each_new_connector_in_state(state, connector, connector_state, i)
-		drm_atomic_connector_print_state(&p, connector_state);
+		drm_atomic_connector_print_state(p, connector_state);
 }
+EXPORT_SYMBOL(drm_atomic_print_new_state);
 
 static void __drm_state_dump(struct drm_device *dev, struct drm_printer *p,
 			     bool take_locks)

drivers/gpu/drm/drm_atomic_uapi.c

···
  * Copyright (C) 2014 Red Hat
  * Copyright (C) 2014 Intel Corp.
  * Copyright (C) 2018 Intel Corp.
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
···
 	struct drm_out_fence_state *fence_state;
 	int ret = 0;
 	unsigned int i, j, num_fences;
+	struct drm_printer p = drm_info_printer(dev->dev);
 
 	/* disallow for drivers not supporting atomic: */
 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
···
 		ret = drm_atomic_nonblocking_commit(state);
 	} else {
 		if (drm_debug_enabled(DRM_UT_STATE))
-			drm_atomic_print_state(state);
+			drm_atomic_print_new_state(state, &p);
 
 		ret = drm_atomic_commit(state);
 	}

drivers/gpu/drm/drm_crtc_internal.h

···
  *   Jesse Barnes <[e-mail]>
  * Copyright © 2014 Intel Corporation
  *   Daniel Vetter <[e-mail]>
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
···
 int __drm_atomic_helper_set_config(struct drm_mode_set *set,
 				   struct drm_atomic_state *state);
 
-void drm_atomic_print_state(const struct drm_atomic_state *state);
+void drm_atomic_print_new_state(const struct drm_atomic_state *state,
+		struct drm_printer *p);
 
 /* drm_atomic_uapi.c */
 int drm_atomic_connector_commit_dpms(struct drm_atomic_state *state,

drivers/gpu/drm/selftests/test-drm_framebuffer.c

···
 #include <drm/drm_device.h>
 #include <drm/drm_mode.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_print.h>
 
 #include "../drm_crtc_internal.h"