ASoC: omap-abe-twl6040: Fix missing audio card caused by deferred probing

BugLink: https://bugs.launchpad.net/bugs/1837161
[ Upstream commit 76836fd354922ebe4798a64fda01f8dc6a8b0984 ]

The machine driver fails to probe in next-20181113 with:

[    2.539093] omap-abe-twl6040 sound: ASoC: CODEC DAI twl6040-legacy not registered
[    2.546630] omap-abe-twl6040 sound: devm_snd_soc_register_card() failed: -517
...
[    3.693206] omap-abe-twl6040 sound: ASoC: Both platform name/of_node are set for TWL6040
[    3.701446] omap-abe-twl6040 sound: ASoC: failed to init link TWL6040
[    3.708007] omap-abe-twl6040 sound: devm_snd_soc_register_card() failed: -22
[    3.715148] omap-abe-twl6040: probe of sound failed with error -22

Bisect pointed to a merge commit:
first bad commit: [0f688ab20a540aafa984c5dbd68a71debebf4d7f] Merge remote-tracking branch 'net-next/master'

and a diff between a working kernel does not reveal anything which would
explain the change in behavior.

Further investigation showed that on the second try of loading fails
because the dai_link->platform is no longer NULL and it might be pointing
to uninitialized memory.

The fix is to move the snd_soc_dai_link and snd_soc_card inside of the
abe_twl6040 struct, which is dynamically allocated every time the driver
probes.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/sound/soc/omap/omap-abe-twl6040.c b/sound/soc/omap/omap-abe-twl6040.c
index 614b18d2f631b80c61e32eaca0b139c816fcb5d5..6fd143799534d82118386a681fb04c97b365e402 100644 (file)
--- a/sound/soc/omap/omap-abe-twl6040.c
+++ b/sound/soc/omap/omap-abe-twl6040.c
@@ -36,6 +36,8 @@
 #include "../codecs/twl6040.h"
 
 struct abe_twl6040 {
+       struct snd_soc_card card;
+       struct snd_soc_dai_link dai_links[2];
        int     jack_detection; /* board can detect jack events */
        int     mclk_freq;      /* MCLK frequency speed for twl6040 */
 };
@@ -208,40 +210,10 @@ static int omap_abe_dmic_init(struct snd_soc_pcm_runtime *rtd)
                                ARRAY_SIZE(dmic_audio_map));
 }
 
-/* Digital audio interface glue - connects codec <--> CPU */
-static struct snd_soc_dai_link abe_twl6040_dai_links[] = {
-       {
-               .name = "TWL6040",
-               .stream_name = "TWL6040",
-               .codec_dai_name = "twl6040-legacy",
-               .codec_name = "twl6040-codec",
-               .init = omap_abe_twl6040_init,
-               .ops = &omap_abe_ops,
-       },
-       {
-               .name = "DMIC",
-               .stream_name = "DMIC Capture",
-               .codec_dai_name = "dmic-hifi",
-               .codec_name = "dmic-codec",
-               .init = omap_abe_dmic_init,
-               .ops = &omap_abe_dmic_ops,
-       },
-};
-
-/* Audio machine driver */
-static struct snd_soc_card omap_abe_card = {
-       .owner = THIS_MODULE,
-
-       .dapm_widgets = twl6040_dapm_widgets,
-       .num_dapm_widgets = ARRAY_SIZE(twl6040_dapm_widgets),
-       .dapm_routes = audio_map,
-       .num_dapm_routes = ARRAY_SIZE(audio_map),
-};
-
 static int omap_abe_probe(struct platform_device *pdev)
 {
        struct device_node *node = pdev->dev.of_node;
-       struct snd_soc_card *card = &omap_abe_card;
+       struct snd_soc_card *card;
        struct device_node *dai_node;
        struct abe_twl6040 *priv;
        int num_links = 0;
@@ -252,12 +224,18 @@ static int omap_abe_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       card->dev = &pdev->dev;
-
        priv = devm_kzalloc(&pdev->dev, sizeof(struct abe_twl6040), GFP_KERNEL);
        if (priv == NULL)
                return -ENOMEM;
 
+       card = &priv->card;
+       card->dev = &pdev->dev;
+       card->owner = THIS_MODULE;
+       card->dapm_widgets = twl6040_dapm_widgets;
+       card->num_dapm_widgets = ARRAY_SIZE(twl6040_dapm_widgets);
+       card->dapm_routes = audio_map;
+       card->num_dapm_routes = ARRAY_SIZE(audio_map);
+
        if (snd_soc_of_parse_card_name(card, "ti,model")) {
                dev_err(&pdev->dev, "Card name is not provided\n");
                return -ENODEV;
@@ -274,14 +252,27 @@ static int omap_abe_probe(struct platform_device *pdev)
                dev_err(&pdev->dev, "McPDM node is not provided\n");
                return -EINVAL;
        }
-       abe_twl6040_dai_links[0].cpu_of_node = dai_node;
-       abe_twl6040_dai_links[0].platform_of_node = dai_node;
+
+       priv->dai_links[0].name = "DMIC";
+       priv->dai_links[0].stream_name = "TWL6040";
+       priv->dai_links[0].cpu_of_node = dai_node;
+       priv->dai_links[0].platform_of_node = dai_node;
+       priv->dai_links[0].codec_dai_name = "twl6040-legacy";
+       priv->dai_links[0].codec_name = "twl6040-codec";
+       priv->dai_links[0].init = omap_abe_twl6040_init;
+       priv->dai_links[0].ops = &omap_abe_ops;
 
        dai_node = of_parse_phandle(node, "ti,dmic", 0);
        if (dai_node) {
                num_links = 2;
-               abe_twl6040_dai_links[1].cpu_of_node = dai_node;
-               abe_twl6040_dai_links[1].platform_of_node = dai_node;
+               priv->dai_links[1].name = "TWL6040";
+               priv->dai_links[1].stream_name = "DMIC Capture";
+               priv->dai_links[1].cpu_of_node = dai_node;
+               priv->dai_links[1].platform_of_node = dai_node;
+               priv->dai_links[1].codec_dai_name = "dmic-hifi";
+               priv->dai_links[1].codec_name = "dmic-codec";
+               priv->dai_links[1].init = omap_abe_dmic_init;
+               priv->dai_links[1].ops = &omap_abe_dmic_ops;
        } else {
                num_links = 1;
        }
@@ -300,7 +291,7 @@ static int omap_abe_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       card->dai_link = abe_twl6040_dai_links;
+       card->dai_link = priv->dai_links;
        card->num_links = num_links;
 
        snd_soc_card_set_drvdata(card, priv);