ASoC: tas2770: Fix set_tdm_slot in case of single slot

[ Upstream commit e59bf547a7dd366f93bfebb7487959580ca6c0ec ]

There's a special branch in the set_tdm_slot op for the case of nslots
being 1, but:

 (1) That branch can never work (there's a check for tx_mask being
     non-zero, later there's another check for it *being* zero; one or
     the other always throws -EINVAL).

 (2) The intention of the branch seems to be what the general other
     branch reduces to in case of nslots being 1.

For those reasons remove the 'nslots being 1' special case.

Fixes: 1a476abc723e ("tas2770: add tas2770 smart PA kernel driver")
Suggested-by: Jos Dehaes <jos.dehaes@gmail.com>
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20221027095800.16094-1-povik+lin@cutebit.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 5782896daf651f5c62b1f51d74c1788ccd9daa04)
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c
index a13b086a072be0a76f1a7896fdaedca36b1d2ef2..ec0df3b1ef615ccb95b624c705188cd2e917bdbe 100644 (file)
--- a/sound/soc/codecs/tas2770.c
+++ b/sound/soc/codecs/tas2770.c
@@ -395,21 +395,13 @@ static int tas2770_set_dai_tdm_slot(struct snd_soc_dai *dai,
        if (tx_mask == 0 || rx_mask != 0)
                return -EINVAL;
 
-       if (slots == 1) {
-               if (tx_mask != 1)
-                       return -EINVAL;
-
-               left_slot = 0;
-               right_slot = 0;
+       left_slot = __ffs(tx_mask);
+       tx_mask &= ~(1 << left_slot);
+       if (tx_mask == 0) {
+               right_slot = left_slot;
        } else {
-               left_slot = __ffs(tx_mask);
-               tx_mask &= ~(1 << left_slot);
-               if (tx_mask == 0) {
-                       right_slot = left_slot;
-               } else {
-                       right_slot = __ffs(tx_mask);
-                       tx_mask &= ~(1 << right_slot);
-               }
+               right_slot = __ffs(tx_mask);
+               tx_mask &= ~(1 << right_slot);
        }
 
        if (tx_mask != 0 || left_slot >= slots || right_slot >= slots)