[PATCH v2 1/3] ASoC: hdac_hda: Allocate the private data at codec driver bind

[Peter Ujfalusi <peter.ujfalusi@linux.intel.com>]

The SOF HDA code allocates struct hdac_hda_priv and stores it as drvdata
of the codec device before the codec driver is bound. The driver core
clears drvdata on unbind, so after unbinding the codec driver via sysfs
a subsequent bind dereferences a NULL pointer in hdac_hda_dev_probe().

All information in the private data can be derived from the codec
device itself, so allocate and set it up in hdac_hda_dev_probe() as a
device managed resource, which is released on unbind.

Remove the allocation from SOF, keeping the check for iDisp codecs
without display audio component.

Fixes: 3fd63658caed ("ASoC: Intel: Drop hdac_ext usage for codec device creation")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
---
 sound/soc/codecs/hdac_hda.c     | 13 ++++++++++++-
 sound/soc/sof/intel/hda-codec.c | 23 ++++-------------------
 2 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/sound/soc/codecs/hdac_hda.c b/sound/soc/codecs/hdac_hda.c
index 7414be08d3d5..46617fc88277 100644
--- a/sound/soc/codecs/hdac_hda.c
+++ b/sound/soc/codecs/hdac_hda.c
@@ -619,10 +619,21 @@ static const struct snd_soc_component_driver hdac_hda_hdmi_codec = {
 
 static int hdac_hda_dev_probe(struct hdac_device *hdev)
 {
-	struct hdac_hda_priv *hda_pvt = dev_get_drvdata(&hdev->dev);
+	struct hdac_hda_priv *hda_pvt;
 	struct hdac_ext_link *hlink;
 	int ret;
 
+	hda_pvt = devm_kzalloc(&hdev->dev, sizeof(*hda_pvt), GFP_KERNEL);
+	if (!hda_pvt)
+		return -ENOMEM;
+
+	hda_pvt->codec = dev_to_hda_codec(&hdev->dev);
+	hda_pvt->dev_index = hdev->addr;
+	/* Intel iDisp (HDMI/DP) codec */
+	if (((hdev->vendor_id >> 16) & 0xFFFF) == 0x8086)
+		hda_pvt->need_display_power = true;
+	dev_set_drvdata(&hdev->dev, hda_pvt);
+
 	/* hold the ref while we probe */
 	hlink = snd_hdac_ext_bus_get_hlink_by_name(hdev->bus, dev_name(&hdev->dev));
 	if (!hlink) {
diff --git a/sound/soc/sof/intel/hda-codec.c b/sound/soc/sof/intel/hda-codec.c
index 91f7ca22a4a7..a2b2ecf1e7e6 100644
--- a/sound/soc/sof/intel/hda-codec.c
+++ b/sound/soc/sof/intel/hda-codec.c
@@ -15,8 +15,6 @@
 #include "hda.h"
 
 #if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_AUDIO_CODEC)
-#include "../../codecs/hdac_hda.h"
-
 #define CODEC_PROBE_RETRIES	3
 
 #define IDISP_VID_INTEL	0x80860000
@@ -148,7 +146,6 @@ static struct hda_codec *hda_codec_device_init(struct hdac_bus *bus, int addr, i
 /* probe individual codec */
 static int hda_codec_probe(struct snd_sof_dev *sdev, int address)
 {
-	struct hdac_hda_priv *hda_priv;
 	struct hda_bus *hbus = sof_to_hbus(sdev);
 	struct hda_codec *codec;
 	u32 hda_cmd = (address << 28) | (AC_NODE_ROOT << 20) |
@@ -168,27 +165,15 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address)
 	dev_dbg(sdev->dev, "HDA codec #%d probed OK: response: %x\n",
 		address, resp);
 
-	hda_priv = devm_kzalloc(sdev->dev, sizeof(*hda_priv), GFP_KERNEL);
-	if (!hda_priv)
-		return -ENOMEM;
-
 	codec = hda_codec_device_init(&hbus->core, address, HDA_DEV_LEGACY);
 	ret = PTR_ERR_OR_ZERO(codec);
 	if (ret < 0)
 		return ret;
 
-	hda_priv->codec = codec;
-	hda_priv->dev_index = address;
-	dev_set_drvdata(&codec->core.dev, hda_priv);
-
-	if ((resp & 0xFFFF0000) == IDISP_VID_INTEL) {
-		if (!hbus->core.audio_component) {
-			dev_dbg(sdev->dev,
-				"iDisp hw present but no driver\n");
-			ret = -ENOENT;
-			goto out;
-		}
-		hda_priv->need_display_power = true;
+	if ((resp & 0xFFFF0000) == IDISP_VID_INTEL && !hbus->core.audio_component) {
+		dev_dbg(sdev->dev, "iDisp hw present but no driver\n");
+		ret = -ENOENT;
+		goto out;
 	}
 
 	if (is_generic_config(hbus))
-- 
2.56.0