[PATCH v3 00/13] drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup

Jonas Karlman
2026-04-03T18:53:36Z

This is a revival of an old dw-hdmi series and is the first series part
of a new effort to upstream old LibreELEC HDMI 2.0 patches for Rockchip
RK33xx devices.

This series ensure poweron/poweroff and CEC phys addr invalidation is
happening under drm mode_config mutex lock, and also ensure EDID is
updated after a HPD low voltage pulse by changing to debounce hotplug
processing.

These changes have mainly been tested on Rockchip RK3328, RK3399 and
RK3568 devices.

Rockchip uses the dw-hdmi connector, so this could use some more testing
with drivers that use the bridge connector.

Future planned series will likely convert dw-hdmi to a hdmi bridge and
add improved deep color support as preparation to add 10-bit and yuv420
output support on Rockchip RK33xx devices.

Testing with a Rock Pi 4 (RK3399) using a Reaspberry Pi Monitor with
Linux kms client console using drm.debug=0xe should log something like
following:

Power cycle monitor using the power button:
[CONNECTOR:68:HDMI-A-1] CEA VCDB 0x4a
[CONNECTOR:68:HDMI-A-1] HDMI: DVI dual 0, max TMDS clock 0 kHz
[CONNECTOR:68:HDMI-A-1] ELD monitor RPI MON156
[CONNECTOR:68:HDMI-A-1] HDMI: latency present 0 0, video latency 0 0, audio latency 0 0
[CONNECTOR:68:HDMI-A-1] ELD size 36, SAD count 1
[CONNECTOR:68:HDMI-A-1] Same epoch counter 10

Cable unplugged:
[CONNECTOR:68:HDMI-A-1] EDID changed, epoch counter 11
[CONNECTOR:68:HDMI-A-1] status updated from connected to disconnected
[CONNECTOR:68:HDMI-A-1] Changed epoch counter 10 => 12
[CONNECTOR:68:HDMI-A-1] generating connector hotplug event
[CONNECTOR:68:HDMI-A-1] Sent hotplug event

Cable connected:
[CONNECTOR:68:HDMI-A-1] CEA VCDB 0x4a
[CONNECTOR:68:HDMI-A-1] HDMI: DVI dual 0, max TMDS clock 0 kHz
[CONNECTOR:68:HDMI-A-1] ELD monitor RPI MON156
[CONNECTOR:68:HDMI-A-1] HDMI: latency present 0 0, video latency 0 0, audio latency 0 0
[CONNECTOR:68:HDMI-A-1] ELD size 36, SAD count 1
[CONNECTOR:68:HDMI-A-1] status updated from disconnected to connected
[CONNECTOR:68:HDMI-A-1] Changed epoch counter 12 => 13
[CONNECTOR:68:HDMI-A-1] generating connector hotplug event
[CONNECTOR:68:HDMI-A-1] Sent hotplug event

Changes in v3:
- Rework EDID refresh handling to closer match bridge connector
- Use delayed work to debounce HPD processing
- Update commit messages
- Collect r-b tags
- Rebased on next-20260401
Link to v2: https://lore.kernel.org/r/20240908132823.3308029-1-jonas@kwiboo.se/

Changes in v2:
- Add patch to disable scrambler feature when not supported
- Add patch to only notify connected status on HPD interrupt
- Update commit messages
- Collect r-b tags
- Rebased on next-20240906
Link to v1: https://lore.kernel.org/r/20240611155108.1436502-1-jonas@kwiboo.se/

Jonas Karlman (13):
drm: bridge: dw_hdmi: Disable scrambler feature when not supported
drm: bridge: dw_hdmi: Only notify connected status on HPD interrupt
drm: bridge: dw_hdmi: Call poweron/poweroff from atomic enable/disable
drm: bridge: dw_hdmi: Use passed mode instead of stored previous_mode
drm: bridge: dw_hdmi: Fold poweron and setup functions
drm: bridge: dw_hdmi: Remove previous_mode and mode_set
drm: bridge: dw_hdmi: Invalidate CEC phys addr from connector detect
drm: bridge: dw_hdmi: Remove cec_notifier_mutex
drm: bridge: dw_hdmi: Use delayed_work to debounce hotplug event
drm: bridge: dw_hdmi: Use drm_connector_helper_hpd_irq_event()
drm: bridge: dw_hdmi: Extract dw_hdmi_connector_status_update()
drm: bridge: dw_hdmi: Use dw_hdmi_connector_status_update()
drm: bridge: dw_hdmi: Use display_info is_hdmi and has_audio

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 209 +++++++++-------------
1 file changed, 80 insertions(+), 129 deletions(-)

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2.53.0