[PATCH v4 00/10] Synopsys DisplayPort Controller improvements for Rockchip platforms

From: Sebastian Reichel

Date: Tue Jul 21 2026 - 15:08:42 EST


This patch series updates the Synopsys Designware DisplayPort bridge
together with the only existing user: The Rockchip RK3576/RK3588:

1. follow-up bridges (PHY, USB-C connector)
this is needed to get USB-C DP AltMode working; I've followed the
Qualcomm driver as reference

2. runtime PM
the initial driver has been upstreamed without RPM; add it to
avoid wasting power when nothing is plugged

3. audio
the initial driver has been upstreamed without audio support;
this adds all missing bits for audio with single stream transport

To properly make use of the bridge code the following USBDP PHY series
is also needed:

https://lore.kernel.org/all/20260714-rockchip-usbdp-cleanup-v13-0-6cb3e769d4c5@xxxxxxxxxxxxx/

There are two parts, which possibly need some discussion:

1. I added a dedicated bridge callback for out-of-band hotplug events,
which is separate from the hotplug_notify. I have a feeling, that
there might be a better solution, but haven't found it.

2. The DT binding for audio support works perfectly fine, but is not
really ready for MST. I don't intend to implement MST right now,
but the binding should obviously take it into consideration to
avoid breaking it in the future. I've put different options into
the patch description and went with the easy one, which is easy to
test.

Changes in PATCHv4:
- Link to v3: https://lore.kernel.org/all/20260612-synopsys-dw-dp-improvements-v3-0-dc61e6352508@xxxxxxxxxxxxx/
- Drop "Simplify driver data setting" (effectively reverted later on)
- Add "Fix incorrect resource lifetimes in bind callback", which
affects all following patches quite a bit (Sashiko)
- Update "Add follow-up bridge support" to mention that fatal errors
are fine (Sashiko)
- Update "Add out-of-band HPD notify handler" to use
drm_for_each_bridge_in_chain() instead of
drm_for_each_bridge_in_chain_scoped() required after rebase to
latest drm-misc-next
- Add 100ms sleep in hpd detect functions after runtime resume in the
"Add Runtime PM support" patch (Andy Yan)
- Keep runtime PM enabled if DP is used without USB-C to avoid missing
HPD signals in "Add Runtime PM support" patch (Andy Yan)
- Update patch description of DT binding patch and drop RFC tag
- Use pm_runtime_resume_and_get() in the audio startup function, which
allows easy error handling (Sashiko)
- Avoid updating audio_interface in the audio prepare function when
an error related early exit happens (Sashiko)
- Add error handling for clock prepare calls in audio prepare function
(Sashiko)

Changes in PATCHv3:
- Link to v2: https://lore.kernel.org/r/20260501-synopsys-dw-dp-improvements-v2-0-d7e7f6bac77f@xxxxxxxxxxxxx
- Collect Reviewed-by on "Simplify driver data setting" patch (Andy Yan)
- Use of_drm_get_bridge_by_endpoint instead of devm_drm_of_get_bridge (Luca Ceresoli)
- Use FIELD_PREP_WM16 instead of FIELD_PREP_WM16_CONST (Chaoyi Chen)
- Rebase to latest drm-misc-next (Dropped Cristian's patches)

Changes in PATCHv2:
* Link to v1: https://lore.kernel.org/r/20260326-synopsys-dw-dp-improvements-v1-0-501849162290@xxxxxxxxxxxxx
* rebased to latest drm-misc-next
* prepended the Patches from Cristian's cleanup series, as they also
needed a rebase and should be merged first
https://lore.kernel.org/dri-devel/20260327-drm-rk-fixes-v3-0-fd2e6900c08c@xxxxxxxxxxxxx/
* fix issue with the audio stream (un)prepare handling in last patch

Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
---
Sebastian Reichel (10):
drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
drm/bridge: synopsys: dw-dp: Support MEDIA_BUS_FMT_FIXED
drm/bridge: synopsys: dw-dp: Add follow-up bridge support
drm/bridge: Add out-of-band HPD notify handler
drm/bridge: synopsys: dw-dp: Support software triggered OOB HPD
drm/rockchip: dw_dp: Implement out-of-band HPD handling
drm/bridge: synopsys: dw-dp: Add Runtime PM support
drm/rockchip: dw_dp: Add runtime PM support
dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells
drm/bridge: synopsys: dw-dp: Add audio support

.../bindings/display/rockchip/rockchip,dw-dp.yaml | 9 +-
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 456 ++++++++++++++++++---
drivers/gpu/drm/display/drm_bridge_connector.c | 6 +
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 223 ++++++++--
include/drm/bridge/dw_dp.h | 11 +-
include/drm/drm_bridge.h | 14 +
6 files changed, 629 insertions(+), 90 deletions(-)
---
base-commit: 7296004bd2ceb1284fb557399f0134361f8e34af
change-id: 20260325-synopsys-dw-dp-improvements-7da2e98df1dd

Best regards,
--
Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>