[PATCH v6 00/22] drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup

Jonas Karlman jonas at kwiboo.se
Sat May 16 11:38:10 PDT 2026 

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 during normal DRM funcs, ensures EDID and CEC phys addr is
updated in detect() similar to how the bridge connector works with a
HDMI bridge attached, and also changes to debounce hotplug processing
to prevent a full disable/enable cycle during a HPD low voltage pulse.

After this series HPD, EDID and CEC handling should work very similar
regardless is the dw-hdmi connector or the bridge connector is used.
It should also help ensure a smoother transition when dw-hdmi is fully
converted into a HDMI bridge in a future series.

These changes have mainly been tested on Rockchip RK3328, RK3399 and
RK3568 devices using both the dw-hdmi connector and also using a basic
convert to use a bridge connector. The changes has also been tested on
a Amlogic S905X device that uses 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 [v6]
- 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 [v3]
- drm/rockchip: dw_hdmi: Misc cleanup and propagate bus format [v1]
- drm/rockchip: dw_hdmi: Enable YCbCr and Deep Color modes
Link to snapshot: https://github.com/Kwiboo/linux-rockchip/commits/next-20260508-rk-hdmi-v4/

Changes in v6:
- Update EDID and CEC phys addr in the bridge detect() func
- Add CEC notifier bridge op for the bridge connector
- Change back to disable_delayed_work_sync() in hpd disable ops,
  a possible deadlock is avoided by not using drm_bridge_hpd_notify()
- Drop use of a suspend helper now that hpd disable ops use sync() calls
- Ensure HPD interrupt is masked and IRQ handler is disabled early
  in dw_hdmi_remove() to prevent any irq re-arming of delayed work
- Update a few commit messages and cover letter
- Collect t-b tags
Link to v5: https://lore.kernel.org/dri-devel/20260510124111.1226584-1-jonas@kwiboo.se/

Changes in v5:
- Add patch that holds a bridge ref until connector cleanup, to fix
  a use-after-free issue during connector cleanup
- Add patch that unregister CEC notifier during connector cleanup
- Add patch that adds a common suspend helper
- Add patch that drops call to drm_bridge_hpd_notify()
- Collect r-b tag
- Rebased on next-20260508
Link to v4: https://lore.kernel.org/dri-devel/20260504191059.275928-1-jonas@kwiboo.se/

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/dri-devel/20260403185303.80748-1-jonas@kwiboo.se/

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/dri-devel/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/dri-devel/20240611155108.1436502-1-jonas@kwiboo.se/

Jonas Karlman (22):
  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: Hold bridge ref until connector cleanup
  drm: bridge: dw_hdmi: Unregister CEC notifier during connector cleanup
  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 generic CEC notifier helpers
  drm: bridge: dw_hdmi: Update EDID and CEC phys addr in bridge detect()
  drm: bridge: dw_hdmi: Declare bridge CEC notifier support
  drm: bridge: dw_hdmi: Use display_info is_hdmi and has_audio
  drm: bridge: dw_hdmi: Drop call to drm_bridge_hpd_notify()
  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   | 498 ++++++++------------
 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, 187 insertions(+), 326 deletions(-)

-- 
2.54.0

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