This series converts all the bridge-only callers of the deprecated
drm_of_find_panel_or_bridge() API to a new, simpler API that handles bridge
refcounting.
All patches acked/reviewed except patches 3 and 4.
== Series description
* Patch 1 (new in v2) makes drm_bridge_put() ignore ERR_PTR pointers,
not only NULL pointers
* Patch 2 introduces of_drm_get_bridge_by_endpoint() as a replacement for
bridge-only calls to drm_of_find_panel_or_bridge(); the new function
refcounts the bridge and is simpler
* The following patches convert all bridge-only users to the new API
* The last patch forbids new bridge-only calls to
drm_of_find_panel_or_bridge()
== Grand plan
This is part of the work to support hotplug of DRM bridges. The grand plan
was discussed in [0].
Here's the work breakdown (➜ marks the current series):
1. ➜ add refcounting to DRM bridges struct drm_bridge,
based on devm_drm_bridge_alloc()
A. ✔ add new alloc API and refcounting (v6.16)
B. ✔ convert all bridge drivers to new API (v6.17)
C. ✔ kunit tests (v6.17)
D. ✔ add get/put to drm_bridge_add/remove() + attach/detach()
and warn on old allocation pattern (v6.17)
E. ➜ add get/put on drm_bridge accessors
1. ✔ drm_bridge_chain_get_first_bridge(), add cleanup action (v6.18)
2. ✔ drm_bridge_get_prev_bridge() (v6.18)
3. ✔ drm_bridge_get_next_bridge() (v6.19)
4. ✔ drm_for_each_bridge_in_chain() (v6.19)
5. ✔ drm_bridge_connector_init (v6.19)
6. ✔ protect encoder bridge chain with a mutex (v7.2)
7. ➜ of_drm_find_bridge
a. ✔ add of_drm_get_bridge() (v7.0),
convert basic direct users (v7.0-v7.1)
b. ✔ convert direct of_drm_get_bridge() users, part 2 (v7.0)
c. ✔ convert direct of_drm_get_bridge() users, part 3 (v7.0)
d. ✔ convert direct of_drm_get_bridge() users, part 4 (v7.1-v7.2)
e. ➜ convert bridge-only drm_of_find_panel_or_bridge() users
8. drm_of_find_panel_or_bridge, *_of_get_bridge
9. ✔ enforce drm_bridge_add before drm_bridge_attach (v6.19)
F. ✔ debugfs improvements
1. ✔ add top-level 'bridges' file (v6.16)
2. ✔ show refcount and list lingering bridges (v6.19)
2. … handle gracefully atomic updates during bridge removal
A. ✔ Add drm_bridge_enter/exit() to protect device resources (v7.0)
B. … protect private_obj removal from list
C. ✔ Add drm_bridge_clear_and_put() (v7.1)
3. … DSI host-device driver interaction
4. ✔ removing the need for the "always-disconnected" connector
5. ✔ Migrate i.MX LCDIF driver to bridge-connector (v7.2)
6. … DRM bridge hotplug
A. … Bridge hotplug management in the DRM core
1. ✔ bridge-connector: attach encoder to the connector (v7.2)
B. Device tree description
[0]
https://lore.kernel.org/lkml/[email protected]/#t
Signed-off-by: Luca Ceresoli <[email protected]>
---
Changes in v6:
- Patch 2: fix warning in the no-OF case
- Patch 3: fix too-late next_bridge assignment
- Link to v5:
https://patch.msgid.link/20260507-drm-bridge-alloc-getput-panel_or_bridge-v5-0-472b913b5...@bootlin.com
Changes in v5:
- Patch 1: change drm_bridge_put() only
- Patches 3,10: simplify error management code flow
- Link to v4:
https://patch.msgid.link/20260504-drm-bridge-alloc-getput-panel_or_bridge-v4-0-b578c3daa...@bootlin.com
Changes in v4:
- Fixed patches 3 and 10
- Minor fixes to patches 1 and 2
- Removed bouncing addresses [email protected] and
[email protected] from Cc
- Link to v3:
https://patch.msgid.link/20260428-drm-bridge-alloc-getput-panel_or_bridge-v3-0-a537b5567...@bootlin.com
Changes in v3:
- patch 3, 8, 10: fixed ERR_PTR deref in the -ENODEV case, and removed
Dmitry's R-by from those patches as they are changed
- Added review trailers to the other patches
- Link to v2:
https://patch.msgid.link/20260428-drm-bridge-alloc-getput-panel_or_bridge-v2-0-4300744a1...@bootlin.com
Changes in v2:
- Added patch to ignore ERR_PTR values in drm_bridge_get/put()
- Changed API to return the bridge (or a ERR_PTR) in the return value,
not as a double-pointer output parameter
- Adapted all patches to the new API, dropped Dmitry's review tags as the
patches are all modified
- Removed bouncing addresses from Cc list
- Link to v1:
https://patch.msgid.link/20260413-drm-bridge-alloc-getput-panel_or_bridge-v1-0-acd01cd79...@bootlin.com
---
Luca Ceresoli (11):
drm/bridge: drm_bridge_put(): ignore ERR_PTR
drm/bridge: add of_drm_get_bridge_by_endpoint()
drm/msm/hdmi: switch to of_drm_get_bridge_by_endpoint()
drm/hisilicon/kirin: switch to of_drm_get_bridge_by_endpoint()
drm/bridge: chrontel-ch7033: switch to of_drm_get_bridge_by_endpoint()
drm/bridge: lontium-lt9611uxc: switch to of_drm_get_bridge_by_endpoint()
drm/bridge: lt9611: switch to of_drm_get_bridge_by_endpoint()
drm/bridge: adv7511: switch to of_drm_get_bridge_by_endpoint()
drm/bridge: lt8713sx: switch to of_drm_get_bridge_by_endpoint()
drm: zynqmp_dp: switch to of_drm_get_bridge_by_endpoint()
drm: of: forbid bridge-only calls to drm_of_find_panel_or_bridge()
drivers/gpu/drm/bridge/adv7511/adv7511.h | 1 -
drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 15 +++---
drivers/gpu/drm/bridge/chrontel-ch7033.c | 28 ++++++-----
drivers/gpu/drm/bridge/lontium-lt8713sx.c | 10 ++--
drivers/gpu/drm/bridge/lontium-lt9611.c | 9 ++--
drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 9 ++--
drivers/gpu/drm/drm_bridge.c | 45 +++++++++++++++++-
drivers/gpu/drm/drm_of.c | 26 +++++------
drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c | 9 ++--
drivers/gpu/drm/msm/hdmi/hdmi.c | 70 +++++++++++++++++++---------
drivers/gpu/drm/xlnx/zynqmp_dp.c | 19 ++++----
include/drm/drm_bridge.h | 7 +++
12 files changed, 162 insertions(+), 86 deletions(-)
---
base-commit: 7af78cfbe2b47cd9ecb61480fb74d64b584d8a94
change-id: 20260410-drm-bridge-alloc-getput-panel_or_bridge-42501b38eaad
Best regards,
--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
