Unverified Commit db2b927f authored by Phil Elwell's avatar Phil Elwell Committed by Maxime Ripard
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drm/vc4: hdmi: Disable audio if dmas property is present but empty 



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@vger.kernel.org>
Signed-off-by: default avatarPhil Elwell <phil@raspberrypi.org>
Link: https://lore.kernel.org/r/20220613144800.326124-18-maxime@cerno.tech


Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
parent 7bcb9c8d

drivers/gpu/drm/vc4/vc4_hdmi.c

+3 −3
Original line number Diff line number Diff line
@@ -2035,12 +2035,12 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi) 
	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;

	}