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From:   =?UTF-8?q?Martin=20Povi=C5=A1er?= <povik+lin@cutebit.org>
To:     Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>
Cc:     Stephen Kitt <steve@sk2.org>, Raphael-Xu <13691752556@139.com>,
        Frank Shi <shifu0704@thundersoft.com>, shenghao-ding@ti.com,
        kevin-lu@ti.com, Jos Dehaes <jos.dehaes@gmail.com>,
        alsa-devel@alsa-project.org, asahi@lists.linux.dev,
        linux-kernel@vger.kernel.org,
        =?UTF-8?q?Martin=20Povi=C5=A1er?= <povik+lin@cutebit.org>
Subject: [PATCH 1/3] ASoC: tas2770: Fix set_tdm_slot in case of single slot
Date:   Thu, 27 Oct 2022 11:57:58 +0200
Message-Id: <20221027095800.16094-1-povik+lin@cutebit.org>
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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>
---
 sound/soc/codecs/tas2770.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c
index b6765235a4b3..8557759acb1f 100644
--- 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)
-- 
2.33.0