[PATCH] ASoC: cs35l56: Wait for firmware timer expiry before system suspend

[PATCH] ASoC: cs35l56: Wait for firmware timer expiry before system suspend

[Richard Fitzgerald]

On CS35L5x firmware older than 3.13.7 (B0 silicon) and 4.7.16 (B2 silicon)
a SoundWire bus reset is not allowed within 250ms of the last firmware
timer start.

This is already avoided during runtime suspend by the various idle
timeouts. System suspend can happen at any time so needs special
protection. The driver cannot cancel the firmware timer, so it must wait
long enough for the timer to expire.

The delay is placed in the suspend stage because typically this has less
impact on end users than delays in resuming. The amp is in PS3 power
state when suspending and no new timers will be started in this state.
An extra 10ms is added to the delay to avoid a race on the exact instant
the firmware timer expires.

There is no need to have the delay for every driver instance. The timers
on each amp will expire in parallel, so the delay is only needed once.
A global flag is used so that the first instance to reach its suspend()
callback will delay and then clear the flag. The cs35l56_fw_idle_wait_lock
mutex is to ensure this is still safe if async_suspend was ever enabled
for SoundWire devices.

Fixes: e496112529006 ("ASoC: cs35l56: Add driver for Cirrus Logic CS35L56")
Reported-by: Ferenc Lengyel <leferi99@gmail.com>
Closes: https://github.com/thesofproject/linux/issues/5898
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 include/sound/cs35l56.h           |  4 ++++
 sound/soc/codecs/cs35l56-sdw.c    | 27 +++++++++++++++++++++-
 sound/soc/codecs/cs35l56-shared.c | 38 +++++++++++++++++++++++++++++++
 sound/soc/codecs/cs35l56.c        | 17 ++++++++++++++
 sound/soc/codecs/cs35l56.h        |  1 +
 5 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h
index 45a5df574aa6d..447876ba29541 100644
--- a/include/sound/cs35l56.h
+++ b/include/sound/cs35l56.h
@@ -209,6 +209,9 @@ struct snd_ctl_elem_value;
 
 #define CS35L56_GPIO_FN_GPIO				0x00000001
 
+/* DSP1_FW_VER */
+#define CS35L56_FW_MAIN_VERSION_MASK			GENMASK(19, 0)
+
 /* Mixer input sources */
 #define CS35L56_INPUT_SRC_NONE				0x00
 #define CS35L56_INPUT_SRC_ASP1RX1			0x08
@@ -445,6 +448,7 @@ int cs35l56_cal_set_status_get(struct cs35l56_base *cs35l56_base,
 int cs35l56_read_prot_status(struct cs35l56_base *cs35l56_base,
 			     bool *fw_missing, unsigned int *fw_version);
 void cs35l56_warn_if_firmware_missing(struct cs35l56_base *cs35l56_base);
+bool cs35l56_needs_wait_for_firmware_timer_expiry(struct cs35l56_base *cs35l56_base);
 void cs35l56_log_tuning(struct cs35l56_base *cs35l56_base, struct cs_dsp *cs_dsp);
 int cs35l56_hw_init(struct cs35l56_base *cs35l56_base);
 int cs35l56_get_speaker_id(struct cs35l56_base *cs35l56_base);
diff --git a/sound/soc/codecs/cs35l56-sdw.c b/sound/soc/codecs/cs35l56-sdw.c
index 98bb4542b9143..b2507a6a37c1a 100644
--- a/sound/soc/codecs/cs35l56-sdw.c
+++ b/sound/soc/codecs/cs35l56-sdw.c
@@ -9,6 +9,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/soundwire/sdw.h>
@@ -36,6 +37,9 @@
 #define CS35L56_LATE_READ_POLL_US	10
 #define CS35L56_LATE_READ_TIMEOUT_US	1000
 
+static DEFINE_MUTEX(cs35l56_fw_idle_wait_lock);
+static bool cs35l56_fw_idle_wait_pending;
+
 static int cs35l56_sdw_poll_mem_status(struct sdw_slave *peripheral,
 				       unsigned int mask,
 				       unsigned int match)
@@ -382,14 +386,34 @@ static int __maybe_unused cs35l56_sdw_runtime_resume(struct device *dev)
 	return 0;
 }
 
+static int cs35l56_sdw_system_suspend_prepare(struct device *dev)
+{
+	cs35l56_fw_idle_wait_pending = true;
+
+	return 0;
+}
+
 static int __maybe_unused cs35l56_sdw_system_suspend(struct device *dev)
 {
 	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+	int ret;
 
 	if (cs35l56->sdw_attached)
 		cs35l56_mask_soundwire_interrupts(cs35l56);
 
-	return cs35l56_system_suspend(dev);
+	ret = cs35l56_system_suspend(dev);
+	if (ret < 0)
+		return ret;
+
+	scoped_guard(mutex, &cs35l56_fw_idle_wait_lock) {
+		if (cs35l56_fw_idle_wait_pending && cs35l56->needs_wait_for_fw_idle) {
+			dev_dbg(cs35l56->base.dev, "Wait for FW timer expiry\n");
+			msleep(CS35L56_FW_REQ_ACTIVE_TIMEOUT_MS + 10);
+			cs35l56_fw_idle_wait_pending = false;
+		}
+	}
+
+	return 0;
 }
 
 static int cs35l56_sdw_probe(struct sdw_slave *peripheral, const struct sdw_device_id *id)
@@ -455,6 +479,7 @@ static void cs35l56_sdw_remove(struct sdw_slave *peripheral)
 }
 
 static const struct dev_pm_ops cs35l56_sdw_pm = {
+	.prepare = cs35l56_sdw_system_suspend_prepare,
 	SET_RUNTIME_PM_OPS(cs35l56_sdw_runtime_suspend, cs35l56_sdw_runtime_resume, NULL)
 	SYSTEM_SLEEP_PM_OPS(cs35l56_sdw_system_suspend, cs35l56_system_resume)
 	LATE_SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend_late, cs35l56_system_resume_early)
diff --git a/sound/soc/codecs/cs35l56-shared.c b/sound/soc/codecs/cs35l56-shared.c
index 7b3e37d462d61..b37f65cd4d336 100644
--- a/sound/soc/codecs/cs35l56-shared.c
+++ b/sound/soc/codecs/cs35l56-shared.c
@@ -1379,6 +1379,44 @@ void cs35l56_warn_if_firmware_missing(struct cs35l56_base *cs35l56_base)
 }
 EXPORT_SYMBOL_NS_GPL(cs35l56_warn_if_firmware_missing, "SND_SOC_CS35L56_SHARED");
 
+bool cs35l56_needs_wait_for_firmware_timer_expiry(struct cs35l56_base *cs35l56_base)
+{
+	unsigned int fw_ver;
+	bool prot_sts;
+	int ret;
+
+	switch (cs35l56_base->type) {
+	case 0x54:
+	case 0x56:
+	case 0x57:
+		switch (cs35l56_base->rev) {
+		case 0xb0:
+			ret = cs35l56_read_prot_status(cs35l56_base, &prot_sts, &fw_ver);
+			if (ret)
+				return true;
+
+			if ((fw_ver & CS35L56_FW_MAIN_VERSION_MASK) < 0x30d07)
+				return true;
+
+			return false;
+		case 0xb2:
+			ret = cs35l56_read_prot_status(cs35l56_base, &prot_sts, &fw_ver);
+			if (ret)
+				return true;
+
+			if ((fw_ver & CS35L56_FW_MAIN_VERSION_MASK) < 0x40710)
+				return true;
+
+			return false;
+		default:
+			return false;
+		}
+	default:
+		return false;
+	}
+}
+EXPORT_SYMBOL_NS_GPL(cs35l56_needs_wait_for_firmware_timer_expiry, "SND_SOC_CS35L56_SHARED");
+
 void cs35l56_log_tuning(struct cs35l56_base *cs35l56_base, struct cs_dsp *cs_dsp)
 {
 	__be32 pid, sid, tid;
diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 74129fcc79dce..04402808dcde6 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -1649,6 +1649,10 @@ int cs35l56_system_resume(struct device *dev)
 
 	dev_dbg(dev, "system_resume\n");
 
+	/* Assume the firmware reset to default until we can check it */
+	if (cs35l56->base.init_done)
+		cs35l56->needs_wait_for_fw_idle = true;
+
 	/*
 	 * We might have done a hard reset or the CS35L56 was power-cycled
 	 * so wait for control port to be ready.
@@ -1663,6 +1667,16 @@ int cs35l56_system_resume(struct device *dev)
 	if (ret)
 		return ret;
 
+	if (cs35l56->sdw_peripheral && cs35l56->base.init_done) {
+		ret = pm_runtime_resume_and_get(cs35l56->base.dev);
+		if (ret < 0)
+			return ret;
+
+		cs35l56->needs_wait_for_fw_idle =
+			cs35l56_needs_wait_for_firmware_timer_expiry(&cs35l56->base);
+		pm_runtime_put_autosuspend(cs35l56->base.dev);
+	}
+
 	/* Firmware won't have been loaded if the component hasn't probed */
 	if (!cs35l56->component)
 		return 0;
@@ -2187,6 +2201,9 @@ int cs35l56_init(struct cs35l56_private *cs35l56)
 	if (ret)
 		return dev_err_probe(cs35l56->base.dev, ret, "Failed to write ASP1_CONTROL3\n");
 
+	cs35l56->needs_wait_for_fw_idle =
+		cs35l56_needs_wait_for_firmware_timer_expiry(&cs35l56->base);
+
 	cs35l56->base.init_done = true;
 	complete_all(&cs35l56->init_completion);
 
diff --git a/sound/soc/codecs/cs35l56.h b/sound/soc/codecs/cs35l56.h
index f7cf8aa653e28..b46f410f0e093 100644
--- a/sound/soc/codecs/cs35l56.h
+++ b/sound/soc/codecs/cs35l56.h
@@ -43,6 +43,7 @@ struct cs35l56_private {
 	bool soft_resetting;
 	bool sdw_attached;
 	bool component_registered;
+	bool needs_wait_for_fw_idle;
 	struct completion init_completion;
 
 	int speaker_id;
-- 
2.47.3

Re: [PATCH] ASoC: cs35l56: Wait for firmware timer expiry before system suspend

[Mark Brown]

On Tue, 15 Sep 2026 11:21:10 +0100, Richard Fitzgerald wrote:
> ASoC: cs35l56: Wait for firmware timer expiry before system suspend

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.3

Thanks!

[1/1] ASoC: cs35l56: Wait for firmware timer expiry before system suspend
      https://git.kernel.org/broonie/sound/c/7226c5c21f48

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark