[PATCH v4 00/17] drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup

Jonas Karlman
2026-05-04T19:11:39Z

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.

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

This series has evolved into an initial part of a larger multi series
effort to:
- drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup
- drm/bridge: dw-hdmi: Improve input/output bus format handling
- drm/bridge: dw-hdmi: Convert to a HDMI bridge and use of bridge connector
- drm/bridge: dw-hdmi: Add and use tmds_char_rate_valid() plat data ops
- drm/meson: hdmi: Misc cleanup and use CEC notifier helpers
- phy: rockchip: inno-hdmi: Change TMDS rate handling to configure() ops
- drm/rockchip: dw_hdmi: Misc cleanup and propagate bus format
- drm/rockchip: dw_hdmi: Enable YCbCr and Deep Color modes
Link to snapshot: https://github.com/Kwiboo/linux-rockchip/commits/next-20260430-rk-hdmi-v2/

Changes in v4:
- Change to use generic CEC notifier helpers
- Disable/mask hpd_work until enable_hpd()/hpd_enable()
- Read connector status directly from HW regs in hpd_work
- Continued rework of HDP and RXSENSE interrupt handling
- Collect r-b tags
- Rebased on next-20260430
Link to v3: https://lore.kernel.org/r/

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 (17):
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: 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
drm: bridge: dw_hdmi: Use generic CEC notifier helpers
drm: bridge: dw_hdmi: Use delayed_work to debounce hotplug event
drm: bridge: dw_hdmi: Rework HDP and RXSENSE interrupt handling
drm: bridge: dw_hdmi: Remove the empty dw_hdmi_setup_rx_sense()
drm: bridge: dw_hdmi: Remove the empty dw_hdmi_phy_update_hpd()
drm: bridge: dw_hdmi: Merge top and bottom half IRQ handlers

drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c | 1 -
drivers/gpu/drm/bridge/synopsys/Kconfig | 1 +
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 436 ++++++--------------
drivers/gpu/drm/meson/meson_dw_hdmi.c | 3 -
drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 2 -
drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 2 -
include/drm/bridge/dw_hdmi.h | 6 -
7 files changed, 134 insertions(+), 317 deletions(-)

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2.54.0