From e59bf547a7dd366f93bfebb7487959580ca6c0ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Povi=C5=A1er?= <povik+lin@cutebit.org>
Date: Thu, 27 Oct 2022 11:57:58 +0200
Subject: [PATCH] ASoC: tas2770: Fix set_tdm_slot in case of single slot
Mime-version: 1.0
Content-type: text/plain; charset=UTF-8
Content-transfer-encoding: 8bit
Git-commit: e59bf547a7dd366f93bfebb7487959580ca6c0ec
Patch-mainline: v6.1-rc6
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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)
-- 
2.35.3