drm/vc4: hdmi: Move audio structure offset checks

The HDMI driver unbind hook doesn't have any ALSA-related code anymore, so
let's move the ALSA sanity checks and comments we have to some other part
of the driver dedicated to ALSA.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-47-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -2076,6 +2076,26 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 	int index, len;
 	int ret;
 
+	/*
+	 * ASoC makes it a bit hard to retrieve a pointer to the
+	 * vc4_hdmi structure. Registering the card will overwrite our
+	 * device drvdata with a pointer to the snd_soc_card structure,
+	 * which can then be used to retrieve whatever drvdata we want
+	 * to associate.
+	 *
+	 * However, that doesn't fly in the case where we wouldn't
+	 * register an ASoC card (because of an old DT that is missing
+	 * the dmas properties for example), then the card isn't
+	 * registered and the device drvdata wouldn't be set.
+	 *
+	 * We can deal with both cases by making sure a snd_soc_card
+	 * pointer and a vc4_hdmi structure are pointing to the same
+	 * memory address, so we can treat them indistinctly without any
+	 * issue.
+	 */
+	BUILD_BUG_ON(offsetof(struct vc4_hdmi_audio, card) != 0);
+	BUILD_BUG_ON(offsetof(struct vc4_hdmi, audio) != 0);
+
 	if (!of_find_property(dev->of_node, "dmas", &len) || !len) {
 		dev_warn(dev,
 			 "'dmas' DT property is missing or empty, no HDMI audio\n");
@@ -3082,26 +3102,6 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 static void vc4_hdmi_unbind(struct device *dev, struct device *master,
 			    void *data)
 {
-	/*
-	 * ASoC makes it a bit hard to retrieve a pointer to the
-	 * vc4_hdmi structure. Registering the card will overwrite our
-	 * device drvdata with a pointer to the snd_soc_card structure,
-	 * which can then be used to retrieve whatever drvdata we want
-	 * to associate.
-	 *
-	 * However, that doesn't fly in the case where we wouldn't
-	 * register an ASoC card (because of an old DT that is missing
-	 * the dmas properties for example), then the card isn't
-	 * registered and the device drvdata wouldn't be set.
-	 *
-	 * We can deal with both cases by making sure a snd_soc_card
-	 * pointer and a vc4_hdmi structure are pointing to the same
-	 * memory address, so we can treat them indistinctly without any
-	 * issue.
-	 */
-	BUILD_BUG_ON(offsetof(struct vc4_hdmi_audio, card) != 0);
-	BUILD_BUG_ON(offsetof(struct vc4_hdmi, audio) != 0);
-
 	pm_runtime_disable(dev);
 }