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From:   Richard Fitzgerald <rf@opensource.cirrus.com>
To:     <broonie@kernel.org>
CC:     <alsa-devel@alsa-project.org>, <linux-kernel@vger.kernel.org>,
        <patches@opensource.cirrus.com>,
        Richard Fitzgerald <rf@opensource.cirrus.com>
Subject: [PATCH 3/5] ASoC: cs35l56: Wait for control port ready during system-resume
Date:   Tue, 8 Aug 2023 17:47:00 +0100
Message-ID: <20230808164702.21272-4-rf@opensource.cirrus.com>
In-Reply-To: <20230808164702.21272-1-rf@opensource.cirrus.com>
References: <20230808164702.21272-1-rf@opensource.cirrus.com>
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The CS35L56 could be hard-reset during a system suspend-resume cycle,
either by the codec driver, in cs35l56_system_resume_early(), or by ACPI.
After a hard reset the driver must wait for the control port to be ready
(datasheet tIRS time) before attempting to access the CS35L56.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/cs35l56.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 9560059c867b..094bcbd0a174 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -952,6 +952,12 @@ int cs35l56_system_resume(struct device *dev)
 
 	dev_dbg(dev, "system_resume\n");
 
+	/*
+	 * We might have done a hard reset or the CS35L56 was power-cycled
+	 * so wait for control port to be ready.
+	 */
+	cs35l56_wait_control_port_ready();
+
 	/* Undo pm_runtime_force_suspend() before re-enabling the irq */
 	ret = pm_runtime_force_resume(dev);
 	if (cs35l56->base.irq)
-- 
2.30.2