[PATCH v3 11/33] drm/mediatek: mtk_hdmi: Unregister audio platform device on failure

[AngeloGioacchino Del Regno]

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")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_hdmi.c | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 59a8a81fa0ec..9131c2fdfba8 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;
@@ -1662,6 +1663,11 @@ static const struct hdmi_codec_ops mtk_hdmi_audio_codec_ops = {
 	.no_capture_mute = 1,
 };
 
+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 +1677,22 @@ static int mtk_hdmi_register_audio_driver(struct device *dev)
 		.i2s = 1,
 		.data = hdmi,
 	};
-	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) {
+		platform_device_unregister(hdmi->audio_pdev);
+		return ret;
+	}
 
 	DRM_INFO("%s driver bound to HDMI\n", HDMI_CODEC_DRV_NAME);
 	return 0;
-- 
2.47.0