[PATCH] ARM: dts: sun4i: Enable HDMI support on the Mele A1000

[Stefan Monnier]

Enable the display pipeline and HDMI output.

Signed-off-by: Stefan Monnier <mon...@iro.umontreal.ca>
---
arch/arm/boot/dts/sun4i-a10-a1000.dts | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/arch/arm/boot/dts/sun4i-a10-a1000.dts b/arch/arm/boot/dts/sun4i-a10-a1000.dts
index 8692b11a83c3..af8ab736fd3c 100644
--- a/arch/arm/boot/dts/sun4i-a10-a1000.dts
+++ b/arch/arm/boot/dts/sun4i-a10-a1000.dts
@@ -60,6 +60,17 @@
stdout-path = "serial0:115200n8";
};

+ hdmi-connector {
+ compatible = "hdmi-connector";
+ type = "a";
+
+ port {
+ hdmi_con_in: endpoint {
+ remote-endpoint = <&hdmi_out_con>;
+ };
+ };
+ };
+
leds {
compatible = "gpio-leds";

@@ -133,6 +144,20 @@
status = "okay";
};

+&de {
+ status = "okay";
+};
+
+&hdmi {
+ status = "okay";
+};
+
+&hdmi_out {
+ hdmi_out_con: endpoint {
+ remote-endpoint = <&hdmi_con_in>;
+ };
+};
+
&i2c0 {
status = "okay";

--
2.20.1

[Stefan Monnier]

Stefan Monnier [2020-08-21 13:18:33] wrote:
> Enable the display pipeline and HDMI output.

Hmm... it turns out this patch (appended below) introduces artifacts to
the audio output on my Mele A1000.

It's the same artifacts that I had encountered two years ago on my
Orange Pi mini which were also triggered by adding the HDMI and display
engine nodes to the DTS.

So the problem I had assumed was specific to the Orange Pi mini seems to
be a lot more widespread and might affect many more machines.

For the record, here's the description I had posted back then, it
describes exactly the symptoms I see now (except it's on a Mele A1000):

I've been using an Orange Pi mini for a while now as home server,
including playing the role of jukebox (via MPD).

Recently this isn't working well any more: every 10s or so the music
"jumps" for a fraction of a second. If I try to use `ogg123`
instead of `mpd`, I also get artifacts every 10s or so (tho it
sounds more like loud scratches in that case).

They occur regularly (every 10s, as mentioned) but they don't occur
at the same place in the music every time (e.g. if I start `ogg123`
the first scratch may occur after 4 second, and if I kill the
process and restart, the first scratch will occur after a different
amount of time).

The effect is heard on the "plain audio" output, which in the case of
the Mele A100 comes out on left/right RCA/cinch connectors (on the
Orange Pi mini it was on a 2.5mm headphone jack).

I don't have any device with which to test whether the HDMI audio output
is also affected.


Stefan

[Stefan Monnier]

Stefan Monnier [2020-08-31 15:51:21] wrote:
> Stefan Monnier [2020-08-21 13:18:33] wrote:
>> Enable the display pipeline and HDMI output.
> Hmm... it turns out this patch (appended below) introduces artifacts to
> the audio output on my Mele A1000.

Side note: I can avoid those artefacts if I blacklist the `sun4i-drm` module.


Stefan