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From:   Richard Fitzgerald <rf@opensource.cirrus.com>
To:     <broonie@kernel.org>
CC:     <alsa-devel@alsa-project.org>, <patches@opensource.cirrus.com>,
        <linux-kernel@vger.kernel.org>,
        Richard Fitzgerald <rf@opensource.cirrus.com>
Subject: [PATCH] ASoC: cs42l42: Regmap must use_single_read/write
Date:   Tue, 11 May 2021 14:28:55 +0100
Message-ID: <20210511132855.27159-1-rf@opensource.cirrus.com>
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cs42l42 does not support standard burst transfers so the use_single_read
and use_single_write flags must be set in the regmap config.

Because of this bug, the patch:

commit 0a0eb567e1d4 ("ASoC: cs42l42: Minor error paths fixups")

broke cs42l42 probe() because without the use_single_* flags it causes
regmap to issue a burst read.

However, the missing use_single_* could cause problems anyway because the
regmap cache can attempt burst transfers if these flags are not set.

Fixes: 2c394ca79604 ("ASoC: Add support for CS42L42 codec")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index d7fb6b38fd7c..e4b058a1d6af 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -400,6 +400,9 @@ static const struct regmap_config cs42l42_regmap = {
 	.reg_defaults = cs42l42_reg_defaults,
 	.num_reg_defaults = ARRAY_SIZE(cs42l42_reg_defaults),
 	.cache_type = REGCACHE_RBTREE,
+
+	.use_single_read = true,
+	.use_single_write = true,
 };
 
 static DECLARE_TLV_DB_SCALE(adc_tlv, -9600, 100, false);
-- 
2.20.1