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authorPhil Elwell <phil@raspberrypi.org>2022-06-13 17:47:44 +0300
committerMaxime Ripard <maxime@cerno.tech>2022-06-28 15:55:41 +0300
commitdb2b927f8668adf3ac765e0921cd2720f5c04172 (patch)
tree3e61cf24b21f4bac55ce76e7bdf02fdc68e1e618 /drivers/gpu/drm
parent7bcb9c8d0bc9f3cab8ac2634b056c2e6b63945ca (diff)
downloadlinux-db2b927f8668adf3ac765e0921cd2720f5c04172.tar.xz
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: Phil Elwell <phil@raspberrypi.org> Link: https://lore.kernel.org/r/20220613144800.326124-18-maxime@cerno.tech Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/vc4/vc4_hdmi.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 823d812f4982..ac723776c6e0 100644
--- 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 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;
}