I2C devices with associated pinctrl states (DPAUX I2C controllers)
will change pinctrl state during runtime PM. This requires taking
a mutex, so these devices cannot be marked as IRQ safe.

Discovered through lockdep.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index bec619b9af4e..4eaeb395d5db 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -2047,8 +2047,11 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	 *
 	 * VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
 	 * be used for atomic transfers. ACPI device is not IRQ safe also.
+	 *
+	 * Devices with pinctrl states cannot be marked IRQ-safe as the pinctrl
+	 * state transitions during runtime PM require mutexes.
 	 */
-	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev))
+	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev) && !i2c_dev->dev->pins)
 		pm_runtime_irq_safe(i2c_dev->dev);
 
 	pm_runtime_enable(i2c_dev->dev);

---
base-commit: 4f938c7d3b25d87b356af4106c2682caf8c835a2
change-id: 20260202-i2c-dpaux-irqsafe-edc04628b401

Hi Mikko,

> -	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev))
> +	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev) && !i2c_dev->dev->pins)

I'm sorry, I had to remove your patch. The ->pins member is
conditional to CONFIG_PINCTRL, without it we get this compile
error:

   drivers/i2c/busses/i2c-tegra.c: In function 'tegra_i2c_probe':
>> drivers/i2c/busses/i2c-tegra.c:1842:82: error: 'struct device' has no member named 'pins'
    1842 |         if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev) && !i2c_dev->dev->pins)
         |                                                                                  ^~

Please fix it and resubmit a v2.

Thanks,
Andi

Hi Mikko,

On Mon, Feb 02, 2026 at 01:42:34PM +0900, Mikko Perttunen wrote:
> I2C devices with associated pinctrl states (DPAUX I2C controllers)
> will change pinctrl state during runtime PM. This requires taking
> a mutex, so these devices cannot be marked as IRQ safe.
> 
> Discovered through lockdep.

I removed this sentence...

> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>

... and merged the patch in i2c/i2c-host-2.

Thanks,
Andi

On Thursday, February 5, 2026 7:47 PM Andi Shyti wrote:
> Hi Mikko,
> 
> On Mon, Feb 02, 2026 at 01:42:34PM +0900, Mikko Perttunen wrote:
> > I2C devices with associated pinctrl states (DPAUX I2C controllers)
> > will change pinctrl state during runtime PM. This requires taking
> > a mutex, so these devices cannot be marked as IRQ safe.
> > 
> > Discovered through lockdep.
> 
> I removed this sentence...

Sorry about that.

> 
> > Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
> 
> ... and merged the patch in i2c/i2c-host-2.
> 
> Thanks,
> Andi
> 

Thank you!

Looks like there's a COMPILE_TEST failure so we'll need to do something like ..

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index e11d50750e63..09152088b79f 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1211,7 +1211,7 @@ config I2C_SYNQUACER
 
 config I2C_TEGRA
 	tristate "NVIDIA Tegra internal I2C controller"
-	depends on ARCH_TEGRA || (COMPILE_TEST && (ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC))
+	depends on ARCH_TEGRA || (COMPILE_TEST && (ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC) && PINCTRL)
 	# COMPILE_TEST needs architectures with readsX()/writesX() primitives
 	help
 	  If you say yes to this option, support will be included for the
-- 
2.52.0

Please let me know how you'd like to go about it.

Mikko

On Monday, February 2, 2026 1:42 PM Mikko Perttunen wrote:
> I2C devices with associated pinctrl states (DPAUX I2C controllers)
> will change pinctrl state during runtime PM. This requires taking
> a mutex, so these devices cannot be marked as IRQ safe.
> 
> Discovered through lockdep.

Eh, I guess not lockdep, just normal lock debugging..

> 
> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
> ---
>  drivers/i2c/busses/i2c-tegra.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index bec619b9af4e..4eaeb395d5db 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -2047,8 +2047,11 @@ static int tegra_i2c_probe(struct platform_device *pdev)
>  	 *
>  	 * VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
>  	 * be used for atomic transfers. ACPI device is not IRQ safe also.
> +	 *
> +	 * Devices with pinctrl states cannot be marked IRQ-safe as the pinctrl
> +	 * state transitions during runtime PM require mutexes.
>  	 */
> -	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev))
> +	if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev) && !i2c_dev->dev->pins)
>  		pm_runtime_irq_safe(i2c_dev->dev);
>  
>  	pm_runtime_enable(i2c_dev->dev);
> 
> ---
> base-commit: 4f938c7d3b25d87b356af4106c2682caf8c835a2
> change-id: 20260202-i2c-dpaux-irqsafe-edc04628b401
> 
>