ASoC: stm32: spdifrx: manage rebind issue

The commit e894efef ("ASoC: core: add support to card rebind")
allows to rebind the sound card after a rebind of one of its component.
With this commit, the sound card is actually rebound,
but may be no more functional.

Corrections:
- Call snd_dmaengine_pcm_register() before snd_soc_register_component().
- Call snd_dmaengine_pcm_unregister() and snd_soc_unregister_component()
explicitly from SPDFIRX driver.
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Link: https://lore.kernel.org/r/20200318144125.9163-3-olivier.moysan@st.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/stm/stm32_spdifrx.c

@@ -944,6 +944,22 @@ static int stm32_spdifrx_parse_of(struct platform_device *pdev,
 	return 0;
 }
 
+static int stm32_spdifrx_remove(struct platform_device *pdev)
+{
+	struct stm32_spdifrx_data *spdifrx = platform_get_drvdata(pdev);
+
+	if (spdifrx->ctrl_chan)
+		dma_release_channel(spdifrx->ctrl_chan);
+
+	if (spdifrx->dmab)
+		snd_dma_free_pages(spdifrx->dmab);
+
+	snd_dmaengine_pcm_unregister(&pdev->dev);
+	snd_soc_unregister_component(&pdev->dev);
+
+	return 0;
+}
+
 static int stm32_spdifrx_probe(struct platform_device *pdev)
 {
 	struct stm32_spdifrx_data *spdifrx;
@@ -995,25 +1011,27 @@ static int stm32_spdifrx_probe(struct platform_device *pdev)
 	udelay(2);
 	reset_control_deassert(rst);
 
-	ret = devm_snd_soc_register_component(&pdev->dev,
+	pcm_config = &stm32_spdifrx_pcm_config;
+	ret = snd_dmaengine_pcm_register(&pdev->dev, pcm_config, 0);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "PCM DMA register error %d\n", ret);
+		return ret;
+	}
+
+	ret = snd_soc_register_component(&pdev->dev,
 					 &stm32_spdifrx_component,
 					 stm32_spdifrx_dai,
 					 ARRAY_SIZE(stm32_spdifrx_dai));
-	if (ret)
+	if (ret) {
+		snd_dmaengine_pcm_unregister(&pdev->dev);
 		return ret;
+	}
 
 	ret = stm32_spdifrx_dma_ctrl_register(&pdev->dev, spdifrx);
 	if (ret)
 		goto error;
 
-	pcm_config = &stm32_spdifrx_pcm_config;
-	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, pcm_config, 0);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "PCM DMA register error %d\n", ret);
-		goto error;
-	}
-
 	ret = regmap_read(spdifrx->regmap, STM32_SPDIFRX_IDR, &idr);
 	if (ret)
 		goto error;
@@ -1029,27 +1047,11 @@ static int stm32_spdifrx_probe(struct platform_device *pdev)
 	return ret;
 
 error:
-	if (!IS_ERR(spdifrx->ctrl_chan))
-		dma_release_channel(spdifrx->ctrl_chan);
-	if (spdifrx->dmab)
-		snd_dma_free_pages(spdifrx->dmab);
+	stm32_spdifrx_remove(pdev);
 
 	return ret;
 }
 
-static int stm32_spdifrx_remove(struct platform_device *pdev)
-{
-	struct stm32_spdifrx_data *spdifrx = platform_get_drvdata(pdev);
-
-	if (spdifrx->ctrl_chan)
-		dma_release_channel(spdifrx->ctrl_chan);
-
-	if (spdifrx->dmab)
-		snd_dma_free_pages(spdifrx->dmab);
-
-	return 0;
-}
-
 MODULE_DEVICE_TABLE(of, stm32_spdifrx_ids);
 
 #ifdef CONFIG_PM_SLEEP