[RFC PATCH 01/23] ASoC: soc-core: allow default ch_maps on links with more than 8 DAIs

[Srinivas Kandagatla]

snd_soc_compensate_channel_connection_map() builds the default channel
map from static 8-entry arrays and fails the card for links with more
DAIs. A speaker protection link carrying both the amplifier and the V/I
sense codec DAIs of four speakers has about sixteen.

Keep the static arrays for links that fit, and allocate a per-link map
with the same 1:1, 1:N or N:1 layout for those that do not.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
---
 sound/soc/soc-core.c | 46 +++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 97269b4ee4ca..34d02a39de90 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -915,20 +915,40 @@ static int snd_soc_compensate_channel_connection_map(struct snd_soc_card *card,
 	if (dai_link->ch_maps)
 		goto sanity_check;
 
-	/* check default map size */
-	if (dai_link->num_cpus   > MAX_DEFAULT_CH_MAP_SIZE ||
-	    dai_link->num_codecs > MAX_DEFAULT_CH_MAP_SIZE) {
-		dev_err(card->dev, "soc-core.c needs update default_connection_maps");
-		return -EINVAL;
-	}
+	/*
+	 * Links wider than the static defaults get their own map. The N:M
+	 * check above leaves a single DAI on the shorter side, at index 0.
+	 */
+	if (dai_link->num_cpus   <= MAX_DEFAULT_CH_MAP_SIZE &&
+	    dai_link->num_codecs <= MAX_DEFAULT_CH_MAP_SIZE) {
+		if (dai_link->num_cpus == dai_link->num_codecs)
+			dai_link->ch_maps = default_ch_map_sync;	/* for 1:1 or N:N */
+		else if (dai_link->num_cpus <  dai_link->num_codecs)
+			dai_link->ch_maps = default_ch_map_1cpu;	/* for 1:N */
+		else
+			dai_link->ch_maps = default_ch_map_1codec;	/* for N:1 */
+	} else {
+		int num_maps = max(dai_link->num_cpus, dai_link->num_codecs);
 
-	/* Compensate missing map for ... */
-	if (dai_link->num_cpus == dai_link->num_codecs)
-		dai_link->ch_maps = default_ch_map_sync;	/* for 1:1 or N:N */
-	else if (dai_link->num_cpus <  dai_link->num_codecs)
-		dai_link->ch_maps = default_ch_map_1cpu;	/* for 1:N */
-	else
-		dai_link->ch_maps = default_ch_map_1codec;	/* for N:1 */
+		ch_maps = devm_kcalloc(card->dev, num_maps, sizeof(*ch_maps),
+				       GFP_KERNEL);
+		if (!ch_maps)
+			return -ENOMEM;
+
+		if (dai_link->num_cpus == dai_link->num_codecs) {
+			for (i = 0; i < num_maps; i++) {
+				ch_maps[i].cpu   = i;
+				ch_maps[i].codec = i;
+			}
+		} else if (dai_link->num_cpus <  dai_link->num_codecs) {
+			for (i = 0; i < num_maps; i++)
+				ch_maps[i].codec = i;	/* cpu stays 0 */
+		} else {
+			for (i = 0; i < num_maps; i++)
+				ch_maps[i].cpu = i;	/* codec stays 0 */
+		}
+		dai_link->ch_maps = ch_maps;
+	}
 
 sanity_check:
 	dev_dbg(card->dev, "dai_link %s\n", dai_link->stream_name);
-- 
2.47.3