[PATCH v3 00/22] drm: convert all bridges to devm_drm_bridge_alloc()

Luca Ceresoli luca.ceresoli at bootlin.com
Fri May 9 06:53:26 PDT 2025


devm_drm_bridge_alloc() [0] is the new API to allocate and initialize a DRM
bridge, and the only one supported from now on. It is the first milestone
towards removal of bridges from a still existing DRM pipeline without
use-after-free.

The steps in the grand plan [1] are:

 1. ➜ add refcounting to DRM bridges (struct drm_bridge)
 2. handle gracefully atomic updates during bridge removal
 3. avoid DSI host drivers to have dangling pointers to DSI devices
 4. finish the hotplug bridge work, removing the "always-disconnected"
    connector, moving code to the core and potentially removing the
    hotplug-bridge itself (this needs to be clarified as points 1-3 are
    developed)

This series is part of step 1 of the grand plan.

Current tasks in step 1 of the grand plan:

 A. ✔ add new alloc API and refcounting -> (now in drm-misc-next)
 B. ➜ convert all bridge drivers to new API (this series)
 C. … documentation, kunit tests (v1 under discussion)
 D. after (B), add get/put to drm_bridge_add/remove() + attach/detech()
 E. after (B), convert accessors; this is a large work and can be done
    in chunks
 F. debugfs improvements

More info about this series in the v2 cover [2].

Luca

[0] https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/0cc6aadd7fc1e629b715ea3d1ba537ef2da95eec
[1] https://lore.kernel.org/lkml/20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com/t/#u
[2] https://lore.kernel.org/lkml/20250424-drm-bridge-convert-to-alloc-api-v2-0-8f91a404d86b@bootlin.com/

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
---
Changes in v3:
- Fixed issues reported for some patches
- Added review tags
- Removed patches that have been applied
- Added revert for the exynos patch, applied by mistake
- Update cover with grand plan info and trim some of it
- Updated bouncing e-mail address in Cc list
- Link to v2: https://lore.kernel.org/lkml/20250424-drm-bridge-convert-to-alloc-api-v2-0-8f91a404d86b@bootlin.com/

Changes in v2:
- Improved cover letter with link to commit adding devm_drm_bridge_alloc()
- add review tags
- fix bugs in zynqmp, vc4 patches
- fix patch 1 error code checking
- Link to v1: https://lore.kernel.org/r/20250407-drm-bridge-convert-to-alloc-api-v1-0-42113ff8d9c0@bootlin.com

---
Luca Ceresoli (22):
      Revert "drm/exynos: mic: convert to devm_drm_bridge_alloc() API"
      drm: convert many bridge drivers from devm_kzalloc() to devm_drm_bridge_alloc() API
      drm/bridge: anx7625: convert to devm_drm_bridge_alloc() API
      drm/bridge: cdns-dsi: convert to devm_drm_bridge_alloc() API
      drm/bridge: megachips-stdpxxxx-ge-b850v3-fw: convert to devm_drm_bridge_alloc() API
      drm/bridge: nxp-ptn3460: convert to devm_drm_bridge_alloc() API
      drm/bridge: sii902x: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: dpi: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: dsi: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: hdmi4: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: hdmi5: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: sdi: convert to devm_drm_bridge_alloc() API
      drm/omap: dss: venc: convert to devm_drm_bridge_alloc() API
      drm/rcar-du: dsi: convert to devm_drm_bridge_alloc() API
      drm/bridge: stm_lvds: convert to devm_drm_bridge_alloc() API
      drm/sti: dvo: convert to devm_drm_bridge_alloc() API
      drm: zynqmp_dp: convert to devm_drm_bridge_alloc() API
      drm/bridge: imx8qxp-pixel-combiner: convert to devm_drm_bridge_alloc() API
      drm/bridge: tc358767: convert to devm_drm_bridge_alloc() API
      drm/bridge: add devm_drm_put_bridge()
      drm/bridge: panel: convert to devm_drm_bridge_alloc() API
      drm/todo: add entry to remove devm_drm_put_bridge()

 Documentation/gpu/todo.rst                         | 15 ++++++
 drivers/gpu/drm/adp/adp-mipi.c                     |  8 ++--
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c       |  8 ++--
 drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c |  9 ++--
 drivers/gpu/drm/bridge/analogix/anx7625.c          |  7 ++-
 drivers/gpu/drm/bridge/aux-bridge.c                |  8 ++--
 drivers/gpu/drm/bridge/aux-hpd-bridge.c            |  9 ++--
 drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c     |  8 ++--
 .../gpu/drm/bridge/cadence/cdns-mhdp8546-core.c    |  8 ++--
 drivers/gpu/drm/bridge/chipone-icn6211.c           |  8 ++--
 drivers/gpu/drm/bridge/chrontel-ch7033.c           |  8 ++--
 drivers/gpu/drm/bridge/cros-ec-anx7688.c           |  8 ++--
 drivers/gpu/drm/bridge/fsl-ldb.c                   |  7 ++-
 drivers/gpu/drm/bridge/imx/imx-legacy-bridge.c     |  8 ++--
 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c       |  8 ++--
 .../gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c    | 27 ++++++-----
 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c    |  8 ++--
 drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c       |  8 ++--
 drivers/gpu/drm/bridge/ite-it6263.c                |  8 ++--
 drivers/gpu/drm/bridge/ite-it6505.c                |  8 ++--
 drivers/gpu/drm/bridge/ite-it66121.c               |  8 ++--
 drivers/gpu/drm/bridge/lontium-lt8912b.c           |  8 ++--
 drivers/gpu/drm/bridge/lontium-lt9211.c            |  7 ++-
 drivers/gpu/drm/bridge/lontium-lt9611.c            |  8 ++--
 drivers/gpu/drm/bridge/lvds-codec.c                |  9 ++--
 .../drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c   | 11 ++---
 drivers/gpu/drm/bridge/microchip-lvds.c            |  8 ++--
 drivers/gpu/drm/bridge/nwl-dsi.c                   |  8 ++--
 drivers/gpu/drm/bridge/nxp-ptn3460.c               |  9 ++--
 drivers/gpu/drm/bridge/panel.c                     | 12 ++---
 drivers/gpu/drm/bridge/parade-ps8622.c             |  8 ++--
 drivers/gpu/drm/bridge/parade-ps8640.c             |  8 ++--
 drivers/gpu/drm/bridge/sii902x.c                   |  7 ++-
 drivers/gpu/drm/bridge/sii9234.c                   |  8 ++--
 drivers/gpu/drm/bridge/sil-sii8620.c               |  8 ++--
 drivers/gpu/drm/bridge/simple-bridge.c             |  8 ++--
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c       |  8 ++--
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c      |  8 ++--
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c     |  8 ++--
 drivers/gpu/drm/bridge/tc358762.c                  |  8 ++--
 drivers/gpu/drm/bridge/tc358764.c                  |  8 ++--
 drivers/gpu/drm/bridge/tc358767.c                  | 56 +++++++++++++++-------
 drivers/gpu/drm/bridge/tc358768.c                  |  8 ++--
 drivers/gpu/drm/bridge/tc358775.c                  |  8 ++--
 drivers/gpu/drm/bridge/thc63lvd1024.c              |  8 ++--
 drivers/gpu/drm/bridge/ti-dlpc3433.c               |  8 ++--
 drivers/gpu/drm/bridge/ti-tdp158.c                 |  8 ++--
 drivers/gpu/drm/bridge/ti-tfp410.c                 |  8 ++--
 drivers/gpu/drm/bridge/ti-tpd12s015.c              |  8 ++--
 drivers/gpu/drm/drm_bridge.c                       | 17 +++++++
 drivers/gpu/drm/exynos/exynos_drm_mic.c            |  7 +--
 drivers/gpu/drm/mediatek/mtk_dp.c                  |  8 ++--
 drivers/gpu/drm/mediatek/mtk_dpi.c                 |  8 ++--
 drivers/gpu/drm/mediatek/mtk_dsi.c                 |  8 ++--
 drivers/gpu/drm/mediatek/mtk_hdmi.c                |  8 ++--
 drivers/gpu/drm/meson/meson_encoder_cvbs.c         | 10 ++--
 drivers/gpu/drm/meson/meson_encoder_dsi.c          | 10 ++--
 drivers/gpu/drm/meson/meson_encoder_hdmi.c         | 10 ++--
 drivers/gpu/drm/omapdrm/dss/dpi.c                  |  7 ++-
 drivers/gpu/drm/omapdrm/dss/dsi.c                  |  7 ++-
 drivers/gpu/drm/omapdrm/dss/hdmi4.c                | 26 ++++------
 drivers/gpu/drm/omapdrm/dss/hdmi5.c                | 26 ++++------
 drivers/gpu/drm/omapdrm/dss/sdi.c                  | 25 ++++------
 drivers/gpu/drm/omapdrm/dss/venc.c                 | 23 ++++-----
 drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c        |  8 ++--
 drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c    |  8 ++--
 drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c     |  8 ++--
 drivers/gpu/drm/sti/sti_dvo.c                      | 29 +++++------
 drivers/gpu/drm/stm/lvds.c                         |  7 ++-
 drivers/gpu/drm/xlnx/zynqmp_dp.c                   | 31 +++++-------
 drivers/gpu/drm/xlnx/zynqmp_dpsub.c                |  1 -
 include/drm/drm_bridge.h                           |  4 ++
 72 files changed, 390 insertions(+), 379 deletions(-)
---
base-commit: 94c60d3c1079fc044e356a78ffc68ca7b0603039
change-id: 20250404-drm-bridge-convert-to-alloc-api-614becf62294

Best regards,
-- 
Luca Ceresoli <luca.ceresoli at bootlin.com>




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