[PATCH v1 0/3] drm/bridge: dw-hdmi: allow ignoring rxsense for hotplug

[Ian Ray <ian.ray@gehealthcare.com>]

Commit da09daf88108 ("drm: bridge: dw_hdmi: only trigger hotplug event
on link change") made hotplug detection also consider rxsense: a
disconnect is now reported only when both HPD and rxsense are low.

This is a problem for boards that route the HDMI output through a
downstream device which keeps the TMDS lines permanently loaded. On the
GE B450/B650/B850 (bx50v3) boards an STDP2600 HDMI-to-DP converter is
used, so rxsense is always asserted and a disconnect is never reported,
even though the HPD signal works correctly. The connector is stuck in
the "connected" state.

This series adds an optional 'ignore-rxsense' device tree property that
restores HPD-only detection for such boards, and enables it on the
bx50v3 boards. The change is backward compatible: without the property
the existing behaviour is unchanged, so old device trees are unaffected.

  Patch 1 adds the device tree binding.
  Patch 2 adds the driver support in the common dw-hdmi layer.
  Patch 3 enables the property on the imx6q bx50v3 boards.

  `make dt_binding_check' is clean for the schema.
  `make CHECK_DTBS=y' is clean for the device trees.

Note: The series touches two subsystems. Patches 1-2 target drm-misc;
patch 3 (ARM dts). Sent together for context, but driver support must
land first.

Ian Ray (3):
  dt-bindings: display: synopsys,dw-hdmi: add ignore-rxsense
  drm/bridge: dw-hdmi: optionally ignore rxsense when detecting hotplug
  ARM: dts: imx: bx50v3: ignore HDMI rxsense

 .../bindings/display/bridge/synopsys,dw-hdmi.yaml         | 8 ++++++++
 arch/arm/boot/dts/nxp/imx/imx6q-bx50v3.dtsi               | 5 +++++
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c                 | 6 ++++++
 3 files changed, 19 insertions(+)

-- 
2.47.3