Re: [PATCH 5.15 247/779] drm/meson: encoder_hdmi: switch to bridge DRM_BRIDGE_ATTACH_NO_CONNECTOR

From: Neil Armstrong
Date: Fri Sep 23 2022 - 05:12:11 EST


Hi Greg,

On 13/09/2022 13:22, Greg Kroah-Hartman wrote:
On Mon, Sep 12, 2022 at 08:48:24PM +0200, Stefan Agner wrote:
On 2022-09-12 18:08, Stefan Agner wrote:
On 2022-08-15 19:58, Greg Kroah-Hartman wrote:
From: Neil Armstrong <narmstrong@xxxxxxxxxxxx>

[ Upstream commit 0af5e0b41110e2da872030395231ab19c45be931 ]

This implements the necessary change to no more use the embedded
connector in dw-hdmi and use the dedicated bridge connector driver
by passing DRM_BRIDGE_ATTACH_NO_CONNECTOR to the bridge attach call.

The necessary connector properties are added to handle the same
functionalities as the embedded dw-hdmi connector, i.e. the HDR
metadata, the CEC notifier & other flags.

The dw-hdmi output_port is set to 1 in order to look for a connector
next bridge in order to get DRM_BRIDGE_ATTACH_NO_CONNECTOR working.

HDMI on ODROID-N2+ was working with v5.15.60, and stopped working with
v5.15.61. Reverting this commit (and two dependent refcount leak) to be
the culprit. Reverting just the refcount leaks is not enough to get HDMI
working, so I assume it is this commit.

I haven't investigated much beyond that, maybe its simple a case of a
missing kernel configuration? DRM_DISPLAY_CONNECTOR is compiled, and the
module display_connector is loaded, so that part seemed to have worked.

Any ideas welcome.

FWIW, I track the issue in the HAOS tracker at
https://github.com/home-assistant/operating-system/issues/2120.

It seems that backporting commit 7cd70656d128 ("drm/bridge:
display-connector: implement bus fmts callbacks") fixes the problem
without reverting this commit.

@Greg, can we backport this commit as well?

sure, now queued up, thanks.

Backport of 7cd70656d128 ("drm/bridge: display-connector: implement bus fmts callbacks") is still missing in 5.15-stable.

Thanks,
Neil


greg k-h