Re: [PATCH v4 06/15] drm/dp_tunnel: Switch private_obj initialization to atomic_create_state

Re: [PATCH v4 06/15] drm/dp_tunnel: Switch private_obj initialization to atomic_create_state

[kernel test robot]

:::::: 
:::::: Manual check reason: "high confidence checkpatch report"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20260128-drm-private-obj-reset-v4-6-90891fa3d3b0@redhat.com>
References: <20260128-drm-private-obj-reset-v4-6-90891fa3d3b0@redhat.com>
TO: Maxime Ripard <mripard@kernel.org>
TO: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
TO: Thomas Zimmermann <tzimmermann@suse.de>
TO: David Airlie <airlied@gmail.com>
TO: Simona Vetter <simona@ffwll.ch>

Hi Maxime,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 68b271a3a94cfd6c7695a96b6398b52feb89e2c2]

url:    https://github.com/intel-lab-lkp/linux/commits/Maxime-Ripard/drm-atomic-Make-drm_atomic_private_obj_init-fallible/20260128-205507
base:   68b271a3a94cfd6c7695a96b6398b52feb89e2c2
patch link:    https://lore.kernel.org/r/20260128-drm-private-obj-reset-v4-6-90891fa3d3b0%40redhat.com
patch subject: [PATCH v4 06/15] drm/dp_tunnel: Switch private_obj initialization to atomic_create_state
:::::: branch date: 13 hours ago
:::::: commit date: 13 hours ago
reproduce: (https://download.01.org/0day-ci/archive/20260129/202601290259.AzRE51I1-lkp@intel.com/reproduce)

# many are suggestions rather than must-fix

ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
#29: FILE: drivers/gpu/drm/display/drm_dp_tunnel.c:1500:
+static struct drm_private_state * tunnel_group_atomic_create_state(struct drm_private_obj *obj)

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v4 00/15] drm/atomic: Allocate drm_private_state through a callback

[Maxime Ripard]

Hi,

This series started from my work on the hardware state readout[1], and
was suggested by Dmitry[2].

This series deal with the fact that drm_private_obj (and thus bridges)
are not initialized using the same pattern than any other object. This
series solves that inconsistency by aligning it to what we're doing for
all the other objects.

This was tested on a TI SK-AM62, with three bridges.

Let me know what you think,
Maxime

1: https://lore.kernel.org/dri-devel/20250902-drm-state-readout-v1-0-14ad5315da3f@kernel.org/
2: https://lore.kernel.org/dri-devel/zvqtehg66dbrrdmik6ylo2kdk74umfzo5hbfkizwsb352nlyqv@jgouvmbfwa4x/

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
Changes in v4:
- Fix a circular dependencies between modules by calling
  __drm_atomic_helper_private_obj_create_state from
  __drm_atomic_helper_bridge_reset instead of
  drm_bridge_atomic_create_priv_state()
- Link to v3: https://lore.kernel.org/r/20260119-drm-private-obj-reset-v3-0-b931abe3a5e3@redhat.com

Changes in v3:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v2: https://lore.kernel.org/r/20251014-drm-private-obj-reset-v2-0-6dd60e985e9d@kernel.org

Changes in v2:
- Switch to a new hook instead of reset since some drm_private_objs want
  to persist across suspends
- Drop the call to drm_private_obj_funcs.reset in
  drm_mode_config_reset()
- Link to v1: https://lore.kernel.org/r/20251008-drm-private-obj-reset-v1-0-805ab43ae65a@kernel.org

---
Maxime Ripard (15):
      drm/atomic: Make drm_atomic_private_obj_init fallible
      drm/atomic: Add new atomic_create_state callback to drm_private_obj
      drm/atomic-helper: Add private_obj atomic_create_state helper
      drm/bridge: Switch private_obj initialization to atomic_create_state
      drm/dp_mst: Switch private_obj initialization to atomic_create_state
      drm/dp_tunnel: Switch private_obj initialization to atomic_create_state
      drm/amdgpu: Switch private_obj initialization to atomic_create_state
      drm/arm: komeda: Switch private_obj initialization to atomic_create_state
      drm/ingenic: Switch private_obj initialization to atomic_create_state
      drm/msm: mdp5: Switch private_obj initialization to atomic_create_state
      drm/msm: dpu1: Switch private_obj initialization to atomic_create_state
      drm/omapdrm: Switch private_obj initialization to atomic_create_state
      drm/tegra: Switch private_obj initialization to atomic_create_state
      drm/vc4: Switch private_obj initialization to atomic_create_state
      drm/atomic: Remove state argument to drm_atomic_private_obj_init

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c  |  51 ++---
 .../gpu/drm/arm/display/komeda/komeda_pipeline.h   |   2 +
 .../drm/arm/display/komeda/komeda_private_obj.c    | 208 ++++++++++++++-------
 drivers/gpu/drm/display/drm_dp_mst_topology.c      |  36 ++--
 drivers/gpu/drm/display/drm_dp_tunnel.c            |  25 ++-
 drivers/gpu/drm/drm_atomic.c                       |  22 ++-
 drivers/gpu/drm/drm_atomic_state_helper.c          |  23 +++
 drivers/gpu/drm/drm_bridge.c                       |  30 +--
 drivers/gpu/drm/ingenic/ingenic-drm-drv.c          |  28 +--
 drivers/gpu/drm/ingenic/ingenic-ipu.c              |  28 +--
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c            |  41 ++--
 drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c           |  40 ++--
 drivers/gpu/drm/omapdrm/omap_drv.c                 |  22 ++-
 drivers/gpu/drm/tegra/hub.c                        |  22 ++-
 drivers/gpu/drm/vc4/vc4_kms.c                      |  67 ++++---
 include/drm/drm_atomic.h                           |  20 +-
 include/drm/drm_atomic_state_helper.h              |   3 +
 17 files changed, 436 insertions(+), 232 deletions(-)
---
base-commit: 68b271a3a94cfd6c7695a96b6398b52feb89e2c2
change-id: 20251008-drm-private-obj-reset-ae1e2741027a

Best regards,
-- 
Maxime Ripard <mripard@redhat.com>

[PATCH v4 06/15] drm/dp_tunnel: Switch private_obj initialization to atomic_create_state

[Maxime Ripard]

The DP tunnel implementation relies on a drm_private_obj, that is
initialized by allocating and initializing a state, and then passing it
to drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/display/drm_dp_tunnel.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_tunnel.c b/drivers/gpu/drm/display/drm_dp_tunnel.c
index 43f13a7c79b931beb230f8afe20afa0ebcf5ed8d..2abd714efd19f27697770813b38194e384be87ce 100644
--- a/drivers/gpu/drm/display/drm_dp_tunnel.c
+++ b/drivers/gpu/drm/display/drm_dp_tunnel.c
@@ -1495,11 +1495,26 @@ tunnel_group_duplicate_state(struct drm_private_obj *obj)
 static void tunnel_group_destroy_state(struct drm_private_obj *obj, struct drm_private_state *state)
 {
 	free_group_state(to_group_state(state));
 }
 
+static struct drm_private_state * tunnel_group_atomic_create_state(struct drm_private_obj *obj)
+{
+	struct drm_dp_tunnel_group_state *group_state;
+
+	group_state = kzalloc(sizeof(*group_state), GFP_KERNEL);
+	if (!group_state)
+		return ERR_PTR(-ENOMEM);
+
+	__drm_atomic_helper_private_obj_create_state(obj, &group_state->base);
+	INIT_LIST_HEAD(&group_state->tunnel_states);
+
+	return &group_state->base;
+}
+
 static const struct drm_private_state_funcs tunnel_group_funcs = {
+	.atomic_create_state = tunnel_group_atomic_create_state,
 	.atomic_duplicate_state = tunnel_group_duplicate_state,
 	.atomic_destroy_state = tunnel_group_destroy_state,
 };
 
 /**
@@ -1579,23 +1594,15 @@ drm_dp_tunnel_atomic_get_new_state(struct drm_atomic_state *state,
 }
 EXPORT_SYMBOL(drm_dp_tunnel_atomic_get_new_state);
 
 static bool init_group(struct drm_dp_tunnel_mgr *mgr, struct drm_dp_tunnel_group *group)
 {
-	struct drm_dp_tunnel_group_state *group_state;
-
-	group_state = kzalloc(sizeof(*group_state), GFP_KERNEL);
-	if (!group_state)
-		return false;
-
-	INIT_LIST_HEAD(&group_state->tunnel_states);
-
 	group->mgr = mgr;
 	group->available_bw = -1;
 	INIT_LIST_HEAD(&group->tunnels);
 
-	drm_atomic_private_obj_init(mgr->dev, &group->base, &group_state->base,
+	drm_atomic_private_obj_init(mgr->dev, &group->base, NULL,
 				    &tunnel_group_funcs);
 
 	return true;
 }
 

-- 
2.52.0