drm/mediatek: mtk_hdmi: Unregister audio platform device on failure

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>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250217154836.108895-18-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index ca82bc829cb96446d4d34eeef45848df03bd716b..1018a9a7433f9478acb7513feff0240025f57254 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -173,6 +173,7 @@ 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;
@@ -1662,6 +1663,11 @@ 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);
@@ -1672,13 +1678,20 @@ 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;