[PATCH v6 16/42] drm/mediatek: mtk_hdmi: Unregister audio platform device on failure

AngeloGioacchino Del Regno
2025-02-11T11:34:45Z

The probe function of this driver may fail after registering the
audio platform device: in that case, the state is not getting
cleaned up, leaving this device registered.

Adding up to the mix, should the probe function of this driver
return a probe deferral for N times, we're registering up to N
audio platform devices and, again, never freeing them up.

To fix this, add a pointer to the audio platform device in the
mtk_hdmi structure, and add a devm action to unregister it upon
driver removal or probe failure.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
drivers/gpu/drm/mediatek/mtk_hdmi.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index a5471abf16dd..a9cdeede499f 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -172,6 +172,7 @@ struct mtk_hdmi {
unsigned int sys_offset;
void __iomem *regs;
enum hdmi_colorspace csp;
+ struct platform_device *audio_pdev;
struct hdmi_audio_param aud_param;
bool audio_enable;
bool powered;
@@ -1661,6 +1662,11 @@ static const struct hdmi_codec_ops mtk_hdmi_audio_codec_ops = {
.hook_plugged_cb = mtk_hdmi_audio_hook_plugged_cb,
};

+static void mtk_hdmi_unregister_audio_driver(void *data)
+{
+ platform_device_unregister(data);
+}
+
static int mtk_hdmi_register_audio_driver(struct device *dev)
{
struct mtk_hdmi *hdmi = dev_get_drvdata(dev);
@@ -1671,13 +1677,20 @@ static int mtk_hdmi_register_audio_driver(struct device *dev)
.data = hdmi,
.no_capture_mute = 1,
};
- struct platform_device *pdev;
+ int ret;

- pdev = platform_device_register_data(dev, HDMI_CODEC_DRV_NAME,
- PLATFORM_DEVID_AUTO, &codec_data,
- sizeof(codec_data));
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
+ hdmi->audio_pdev = platform_device_register_data(dev,
+ HDMI_CODEC_DRV_NAME,
+ PLATFORM_DEVID_AUTO,
+ &codec_data,
+ sizeof(codec_data));
+ if (IS_ERR(hdmi->audio_pdev))
+ return PTR_ERR(hdmi->audio_pdev);
+
+ ret = devm_add_action_or_reset(dev, mtk_hdmi_unregister_audio_driver,
+ hdmi->audio_pdev);
+ if (ret)
+ return ret;

DRM_INFO("%s driver bound to HDMI\n", HDMI_CODEC_DRV_NAME);
return 0;
--
2.48.1