This is a note to let you know that I've just added the patch titled
drm/vc4: hdmi: Disable audio if dmas property is present but empty
to the 5.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vc4-hdmi-disable-audio-if-dmas-property-is-present-but-empty.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From db2b927f8668adf3ac765e0921cd2720f5c04172 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@xxxxxxxxxxxxxxx>
Date: Mon, 13 Jun 2022 16:47:44 +0200
Subject: drm/vc4: hdmi: Disable audio if dmas property is present but empty
From: Phil Elwell <phil@xxxxxxxxxxxxxxx>
commit db2b927f8668adf3ac765e0921cd2720f5c04172 upstream.
The dmas property is used to hold the dmaengine channel used for audio
output.
Older device trees were missing that property, so if it's not there we
disable the audio output entirely.
However, some overlays have set an empty value to that property, mostly
to workaround the fact that overlays cannot remove a property. Let's add
a test for that case and if it's empty, let's disable it as well.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220613144800.326124-18-maxime@xxxxxxxxxx
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2035,12 +2035,12 @@ static int vc4_hdmi_audio_init(struct vc
struct device *dev = &vc4_hdmi->pdev->dev;
struct platform_device *codec_pdev;
const __be32 *addr;
- int index;
+ int index, len;
int ret;
- if (!of_find_property(dev->of_node, "dmas", NULL)) {
+ if (!of_find_property(dev->of_node, "dmas", &len) || !len) {
dev_warn(dev,
- "'dmas' DT property is missing, no HDMI audio\n");
+ "'dmas' DT property is missing or empty, no HDMI audio\n");
return 0;
}
Patches currently in stable-queue which might be from phil@xxxxxxxxxxxxxxx are
queue-5.19/drm-vc4-hdmi-disable-audio-if-dmas-property-is-present-but-empty.patch
