[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
>
>