[PATCH] ASoC: rt712-sdca: reset codec at io_init to fix silent headphone

[Tianze Shao]

On ThinkPad X1 Carbon Gen 13 (Lunar Lake, RT712-SDCA version VA) the
3.5mm headphone jack is silent after rebooting from Windows.
rt712_sdca_va_io_init() gates rt712_sdca_calibration() on the persisted
vendor SW_CONFIG1 flag, and io_init writes SW_CONFIG1=1 at the end
regardless of whether the calibration succeeded. Across a warm reboot
the codec keeps power, so SW_CONFIG1 stays unchanged, the calibration
may be skipped, and the retained state can be invalid, leaving the
headphone amp disabled.

This patch mimics the reset sequence in rt711-sdca.c, it adds an
rt712_sdca_reset() helper, and calls it from io_init so the codec is
reset before initialization. RT712_PARA_VERB_CTL,
RT712_HIDDEN_REG_SW_RESET and RT712_HDA_LEGACY_RESET_CTL are already
defined but were unused. The reset clears SW_CONFIG1 and the analog
state so rt712_sdca_calibration() runs from a clean state and
completes.

Problem reproducible: boot Windows (headphone is good) -> reboot
to Linux (silent).
The reproducibility may depend on Windows' behaviour.

Signed-off-by: Tianze Shao <shaotianze@xxxxxxxxxxx>
---
 sound/soc/codecs/rt712-sdca.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/soc/codecs/rt712-sdca.c b/sound/soc/codecs/rt712-sdca.c
index 4796fce084ff..d6353af07380 100644
--- a/sound/soc/codecs/rt712-sdca.c
+++ b/sound/soc/codecs/rt712-sdca.c
@@ -1843,6 +1843,15 @@ static void rt712_sdca_vb_io_init(struct rt712_sdca_priv *rt712)
 	}
 }
 
+static void rt712_sdca_reset(struct rt712_sdca_priv *rt712)
+{
+	rt712_sdca_index_update_bits(rt712, RT712_VENDOR_REG,
+		RT712_PARA_VERB_CTL, RT712_HIDDEN_REG_SW_RESET,
+		RT712_HIDDEN_REG_SW_RESET);
+	rt712_sdca_index_update_bits(rt712, RT712_VENDOR_HDA_CTL,
+		RT712_HDA_LEGACY_RESET_CTL, 0x1, 0x1);
+}
+
 int rt712_sdca_io_init(struct device *dev, struct sdw_slave *slave)
 {
 	struct rt712_sdca_priv *rt712 = dev_get_drvdata(dev);
@@ -1870,6 +1879,8 @@ int rt712_sdca_io_init(struct device *dev, struct sdw_slave *slave)
 
 	pm_runtime_get_noresume(&slave->dev);
 
+	rt712_sdca_reset(rt712);
+
 	rt712_sdca_index_read(rt712, RT712_VENDOR_REG, RT712_JD_PRODUCT_NUM, &val);
 	rt712->hw_id = (val & 0xf000) >> 12;
 	rt712->version_id = (val & 0x0f00) >> 8;

base-commit: 665159e246749578d4e4bfe106ee3b74edcdab18
-- 
2.53.0