[PATCH 0/3] regulator: handle regulator late cleanup race with PM suspend

[PATCH 0/3] regulator: handle regulator late cleanup race with PM suspend

[Joy Zou]

The regulator_init_complete_work fires ~30s after boot to disable
unused regulators via I2C. When this work races with PM suspend, the
I2C adapter may already be suspended, causing a -ESHUTDOWN warning
dump.

This series addresses the race and adds proper suspend power
management for unused LDO regulators.

Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
---
Joy Zou (3):
      regulator: core: use system_freezable_wq for init complete work
      regulator: pfuze100: add set_suspend_disable for LDO ops
      arm64: dts: imx8mq-evk: add regulator-off-in-suspend for VGEN1/VGEN6

 arch/arm64/boot/dts/freescale/imx8mq-evk.dts |  6 ++++++
 drivers/regulator/core.c                     |  6 ++++--
 drivers/regulator/pfuze100-regulator.c       | 17 +++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)
---
base-commit: 34cf6dafc47441dfb6b356a095b89c3585a93714
change-id: 20260716-b4-regulator-pf01-5db03fba4a92

Best regards,
--  
Joy Zou <joy.zou@oss.nxp.com>

[PATCH 1/3] regulator: core: use system_freezable_wq for init complete work

[Joy Zou]

schedule_delayed_work() uses system_wq, which is non-freezable, allowing
regulator_init_complete_work to run concurrently with system suspend. This
work fires ~30s after boot to disable unused regulators via I2C. When it
races with PM suspend, the I2C adapter may already be suspended, triggering
a -ESHUTDOWN warning dump.

[   33.707233] pc : __i2c_transfer+0x36c/0x3c8
[   33.707240] lr : __i2c_transfer+0x36c/0x3c8
[   33.707246] sp : ffff80008239ba50
[   33.707249] x29: ffff80008239ba50 x28: 0000000000000001 x27: 0000000000000000
[   33.707259] x26: 0000000000000000 x25: 0000000000000001 x24: ffff0000c025c0e0
[   33.707268] x23: 0000000000000000 x22: ffff0000c025c0e1 x21: 0000000000000001
[   33.707277] x20: ffff80008239bae8 x19: ffff0000c0f54880 x18: fffffffffffeb320
[   33.707287] x17: 000000040044ffff x16: 0000000000000000 x15: ffff800082086fd8
[   33.707296] x14: 0000000000000000 x13: 0a6465646e657073 x12: 757320656c696877
[   33.707305] x11: 0000000000000058 x10: 0000000000000018 x9 : ffff800082087060
[   33.707314] x8 : 0000000000057fa8 x7 : 000000000000027d x6 : 0000000000000000
[   33.707323] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff
[   33.707333] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c0123480
[   33.707343] Call trace:
[   33.707346]  __i2c_transfer+0x36c/0x3c8 (P)
[   33.707356]  i2c_transfer+0x6c/0xf8
[   33.707364]  i2c_transfer_buffer_flags+0x5c/0xa0
[   33.707372]  regmap_i2c_write+0x20/0x60
[   33.707382]  _regmap_raw_write_impl+0x5cc/0x660
[   33.707389]  _regmap_bus_raw_write+0x60/0x80
[   33.707396]  _regmap_write+0x58/0xc0
[   33.707403]  _regmap_update_bits+0x11c/0x140
[   33.707409]  regmap_update_bits_base+0x54/0x80
[   33.707416]  regulator_disable_regmap+0x40/0x5c
[   33.707424]  _regulator_do_disable+0x94/0xbc
[   33.707435] CPU2 is up
[   33.707433]  regulator_late_cleanup+0xe0/0x1e8
[   33.707442]  class_for_each_device+0x104/0x13c
[   33.707450]  regulator_init_complete_work_function+0x54/0x80
[   33.707458]  process_one_work+0x150/0x290
[   33.707467]  worker_thread+0x180/0x2f4
[   33.707473]  kthread+0x12c/0x204
[   33.707484]  ret_from_fork+0x10/0x20
[   33.707493] ---[ end trace 0000000000000000 ]---

Switch to system_freezable_wq so the work is frozen before any device
is suspended, eliminating the race.

Fixes: 55576cf18537 ("regulator: Defer init completion for a while after late_initcall")
Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
---
 drivers/regulator/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 1797929dfe56..d5d24a940f31 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -27,6 +27,7 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/module.h>
+#include <linux/workqueue.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/regulator.h>
@@ -6882,8 +6883,9 @@ static int __init regulator_init_complete(void)
 	 * we'd only do this on systems that need it, and a kernel
 	 * command line option might be useful.
 	 */
-	schedule_delayed_work(&regulator_init_complete_work,
-			      msecs_to_jiffies(30000));
+	queue_delayed_work(system_freezable_wq,
+			   &regulator_init_complete_work,
+			   msecs_to_jiffies(30000));
 
 	return 0;
 }

-- 
2.34.1

[PATCH 2/3] regulator: pfuze100: add set_suspend_disable for LDO ops

[Joy Zou]

Add set_suspend_disable callback to pfuze100_ldo_regulator_ops to
support regulator-off-in-suspend DTS property for VGEN regulators.
This allows unused LDO regulators to be properly disabled during
system suspend, reducing power consumption.

Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
---
 drivers/regulator/pfuze100-regulator.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/regulator/pfuze100-regulator.c b/drivers/regulator/pfuze100-regulator.c
index 7d56c22b5e40..e6d3a28baadc 100644
--- a/drivers/regulator/pfuze100-regulator.c
+++ b/drivers/regulator/pfuze100-regulator.c
@@ -158,6 +158,22 @@ static int pfuze100_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 	return ret;
 }
 
+static int pfuze100_set_suspend_disable(struct regulator_dev *rdev)
+{
+	struct pfuze_chip *pfuze100 = rdev_get_drvdata(rdev);
+	int id = rdev_get_id(rdev);
+
+	/*
+	 * Set VGENxSTBY and clear VGENxLPWR so that the LDO output is
+	 * disabled when the PMIC receives a STANDBY event.
+	 * EN=1, LPWR=0, STBY=1 results in output Off when STANDBY is asserted.
+	 */
+	return regmap_update_bits(pfuze100->regmap,
+				  pfuze100->regulator_descs[id].stby_reg,
+				  PFUZE100_VGENxSTBY | PFUZE100_VGENxLPWR,
+				  PFUZE100_VGENxSTBY);
+}
+
 static const struct regulator_ops pfuze100_ldo_regulator_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
@@ -165,6 +181,7 @@ static const struct regulator_ops pfuze100_ldo_regulator_ops = {
 	.list_voltage = regulator_list_voltage_linear,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_suspend_disable = pfuze100_set_suspend_disable,
 };
 
 static const struct regulator_ops pfuze100_fixed_regulator_ops = {

-- 
2.34.1

[PATCH 3/3] arm64: dts: imx8mq-evk: add regulator-off-in-suspend for VGEN1/VGEN6

[Joy Zou]

VGEN1 and VGEN6 have no consumers and are not always-on, causing the
regulator cleanup work to race with PM suspend. Mark them as
regulator-off-in-suspend to disable them properly during suspend and
reduce power consumption.

Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
index 5ea04703ddd7..fc0303e44433 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
@@ -299,6 +299,9 @@ vref_reg: vrefddr {
 			vgen1_reg: vgen1 {
 				regulator-min-microvolt = <800000>;
 				regulator-max-microvolt = <1550000>;
+				regulator-state-mem {
+					regulator-off-in-suspend;
+				};
 			};
 
 			vgen2_reg: vgen2 {
@@ -328,6 +331,9 @@ vgen5_reg: vgen5 {
 			vgen6_reg: vgen6 {
 				regulator-min-microvolt = <1800000>;
 				regulator-max-microvolt = <3300000>;
+				regulator-state-mem {
+					regulator-off-in-suspend;
+				};
 			};
 		};
 	};

-- 
2.34.1

Re: [PATCH 1/3] regulator: core: use system_freezable_wq for init complete work

[Frank Li]

On Thu, Jul 16, 2026 at 11:50:53AM +0800, Joy Zou wrote:
> schedule_delayed_work() uses system_wq, which is non-freezable, allowing
> regulator_init_complete_work to run concurrently with system suspend. This
> work fires ~30s after boot to disable unused regulators via I2C. When it
> races with PM suspend, the I2C adapter may already be suspended, triggering
> a -ESHUTDOWN warning dump.
>
> [   33.707233] pc : __i2c_transfer+0x36c/0x3c8
> [   33.707240] lr : __i2c_transfer+0x36c/0x3c8
> [   33.707246] sp : ffff80008239ba50
> [   33.707249] x29: ffff80008239ba50 x28: 0000000000000001 x27: 0000000000000000
> [   33.707259] x26: 0000000000000000 x25: 0000000000000001 x24: ffff0000c025c0e0
> [   33.707268] x23: 0000000000000000 x22: ffff0000c025c0e1 x21: 0000000000000001
> [   33.707277] x20: ffff80008239bae8 x19: ffff0000c0f54880 x18: fffffffffffeb320
> [   33.707287] x17: 000000040044ffff x16: 0000000000000000 x15: ffff800082086fd8
> [   33.707296] x14: 0000000000000000 x13: 0a6465646e657073 x12: 757320656c696877
> [   33.707305] x11: 0000000000000058 x10: 0000000000000018 x9 : ffff800082087060
> [   33.707314] x8 : 0000000000057fa8 x7 : 000000000000027d x6 : 0000000000000000
> [   33.707323] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff
> [   33.707333] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c0123480
> [   33.707343] Call trace:
> [   33.707346]  __i2c_transfer+0x36c/0x3c8 (P)
> [   33.707356]  i2c_transfer+0x6c/0xf8
> [   33.707364]  i2c_transfer_buffer_flags+0x5c/0xa0
> [   33.707372]  regmap_i2c_write+0x20/0x60
> [   33.707382]  _regmap_raw_write_impl+0x5cc/0x660
> [   33.707389]  _regmap_bus_raw_write+0x60/0x80
> [   33.707396]  _regmap_write+0x58/0xc0
> [   33.707403]  _regmap_update_bits+0x11c/0x140
> [   33.707409]  regmap_update_bits_base+0x54/0x80
> [   33.707416]  regulator_disable_regmap+0x40/0x5c
> [   33.707424]  _regulator_do_disable+0x94/0xbc
> [   33.707435] CPU2 is up
> [   33.707433]  regulator_late_cleanup+0xe0/0x1e8
> [   33.707442]  class_for_each_device+0x104/0x13c
> [   33.707450]  regulator_init_complete_work_function+0x54/0x80
> [   33.707458]  process_one_work+0x150/0x290
> [   33.707467]  worker_thread+0x180/0x2f4
> [   33.707473]  kthread+0x12c/0x204
> [   33.707484]  ret_from_fork+0x10/0x20
> [   33.707493] ---[ end trace 0000000000000000 ]---
>
> Switch to system_freezable_wq so the work is frozen before any device
> is suspended, eliminating the race.
>
> Fixes: 55576cf18537 ("regulator: Defer init completion for a while after late_initcall")
> Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/regulator/core.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 1797929dfe56..d5d24a940f31 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -27,6 +27,7 @@
>  #include <linux/regulator/driver.h>
>  #include <linux/regulator/machine.h>
>  #include <linux/module.h>
> +#include <linux/workqueue.h>
>
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/regulator.h>
> @@ -6882,8 +6883,9 @@ static int __init regulator_init_complete(void)
>  	 * we'd only do this on systems that need it, and a kernel
>  	 * command line option might be useful.
>  	 */
> -	schedule_delayed_work(&regulator_init_complete_work,
> -			      msecs_to_jiffies(30000));
> +	queue_delayed_work(system_freezable_wq,
> +			   &regulator_init_complete_work,
> +			   msecs_to_jiffies(30000));
>
>  	return 0;
>  }
>
> --
> 2.34.1
>
>

Re: [PATCH 2/3] regulator: pfuze100: add set_suspend_disable for LDO ops

[Frank Li]

On Thu, Jul 16, 2026 at 11:50:54AM +0800, Joy Zou wrote:
> Add set_suspend_disable callback to pfuze100_ldo_regulator_ops to
> support regulator-off-in-suspend DTS property for VGEN regulators.
> This allows unused LDO regulators to be properly disabled during
> system suspend, reducing power consumption.
>
> Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/regulator/pfuze100-regulator.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/drivers/regulator/pfuze100-regulator.c b/drivers/regulator/pfuze100-regulator.c
> index 7d56c22b5e40..e6d3a28baadc 100644
> --- a/drivers/regulator/pfuze100-regulator.c
> +++ b/drivers/regulator/pfuze100-regulator.c
> @@ -158,6 +158,22 @@ static int pfuze100_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
>  	return ret;
>  }
>
> +static int pfuze100_set_suspend_disable(struct regulator_dev *rdev)
> +{
> +	struct pfuze_chip *pfuze100 = rdev_get_drvdata(rdev);
> +	int id = rdev_get_id(rdev);
> +
> +	/*
> +	 * Set VGENxSTBY and clear VGENxLPWR so that the LDO output is
> +	 * disabled when the PMIC receives a STANDBY event.
> +	 * EN=1, LPWR=0, STBY=1 results in output Off when STANDBY is asserted.
> +	 */
> +	return regmap_update_bits(pfuze100->regmap,
> +				  pfuze100->regulator_descs[id].stby_reg,
> +				  PFUZE100_VGENxSTBY | PFUZE100_VGENxLPWR,
> +				  PFUZE100_VGENxSTBY);
> +}
> +
>  static const struct regulator_ops pfuze100_ldo_regulator_ops = {
>  	.enable = regulator_enable_regmap,
>  	.disable = regulator_disable_regmap,
> @@ -165,6 +181,7 @@ static const struct regulator_ops pfuze100_ldo_regulator_ops = {
>  	.list_voltage = regulator_list_voltage_linear,
>  	.set_voltage_sel = regulator_set_voltage_sel_regmap,
>  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
> +	.set_suspend_disable = pfuze100_set_suspend_disable,
>  };
>
>  static const struct regulator_ops pfuze100_fixed_regulator_ops = {
>
> --
> 2.34.1
>
>

Re: [PATCH 3/3] arm64: dts: imx8mq-evk: add regulator-off-in-suspend for VGEN1/VGEN6

[Frank Li]

On Thu, Jul 16, 2026 at 11:50:55AM +0800, Joy Zou wrote:
> VGEN1 and VGEN6 have no consumers and are not always-on, causing the
> regulator cleanup work to race with PM suspend.

why cause race? You first patch set workqueue to system_freezable_wq

Frank

> Mark them as
> regulator-off-in-suspend to disable them properly during suspend and
> reduce power consumption.
>
> Signed-off-by: Joy Zou <joy.zou@oss.nxp.com>
> ---
>  arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> index 5ea04703ddd7..fc0303e44433 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> @@ -299,6 +299,9 @@ vref_reg: vrefddr {
>  			vgen1_reg: vgen1 {
>  				regulator-min-microvolt = <800000>;
>  				regulator-max-microvolt = <1550000>;
> +				regulator-state-mem {
> +					regulator-off-in-suspend;
> +				};
>  			};
>
>  			vgen2_reg: vgen2 {
> @@ -328,6 +331,9 @@ vgen5_reg: vgen5 {
>  			vgen6_reg: vgen6 {
>  				regulator-min-microvolt = <1800000>;
>  				regulator-max-microvolt = <3300000>;
> +				regulator-state-mem {
> +					regulator-off-in-suspend;
> +				};
>  			};
>  		};
>  	};
>
> --
> 2.34.1
>
>

Re: [PATCH 2/3] regulator: pfuze100: add set_suspend_disable for LDO ops

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 1200 bytes --]

On Thu, Jul 16, 2026 at 11:50:54AM +0800, Joy Zou wrote:
> Add set_suspend_disable callback to pfuze100_ldo_regulator_ops to
> support regulator-off-in-suspend DTS property for VGEN regulators.
> This allows unused LDO regulators to be properly disabled during
> system suspend, reducing power consumption.

> +static int pfuze100_set_suspend_disable(struct regulator_dev *rdev)

This looks to be only used for LDOs but is named like it applies to all
regulators the driver supports.

> +{
> +	struct pfuze_chip *pfuze100 = rdev_get_drvdata(rdev);
> +	int id = rdev_get_id(rdev);
> +
> +	/*
> +	 * Set VGENxSTBY and clear VGENxLPWR so that the LDO output is
> +	 * disabled when the PMIC receives a STANDBY event.
> +	 * EN=1, LPWR=0, STBY=1 results in output Off when STANDBY is asserted.
> +	 */
> +	return regmap_update_bits(pfuze100->regmap,
> +				  pfuze100->regulator_descs[id].stby_reg,
> +				  PFUZE100_VGENxSTBY | PFUZE100_VGENxLPWR,
> +				  PFUZE100_VGENxSTBY);
> +}

This is a fixed bit in the register, but I see other regulators have
_stby_mask configuration.  Are you sure that all the LDOs in all the
regulators covered by this driver have this feature with this exact
control bit?

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Re: [PATCH 1/3] regulator: core: use system_freezable_wq for init complete work

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 987 bytes --]

On Thu, Jul 16, 2026 at 11:50:53AM +0800, Joy Zou wrote:
> schedule_delayed_work() uses system_wq, which is non-freezable, allowing
> regulator_init_complete_work to run concurrently with system suspend. This
> work fires ~30s after boot to disable unused regulators via I2C. When it
> races with PM suspend, the I2C adapter may already be suspended, triggering
> a -ESHUTDOWN warning dump.

> [   33.707233] pc : __i2c_transfer+0x36c/0x3c8
> [   33.707240] lr : __i2c_transfer+0x36c/0x3c8
> [   33.707246] sp : ffff80008239ba50
> [   33.707249] x29: ffff80008239ba50 x28: 0000000000000001 x27: 0000000000000000

Please think hard before including complete backtraces in upstream
reports, they are very large and contain almost no useful information
relative to their size so often obscure the relevant content in your
message. If part of the backtrace is usefully illustrative (it often is
for search engines if nothing else) then it's usually better to pull out
the relevant sections.

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