[PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Oleksij Rempel]

From: Ahmad Fatoum <a.fatoum@pengutronix.de>

rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
the probe path, which may sleep and is not timing-critical.  When the
reset GPIO is provided by a sleeping controller such as an I2C I/O
expander, gpiod_set_value() warns:

  WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61
  Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT)
  Workqueue: events_unbound deferred_probe_work_func
  pc : gpiod_set_value+0x44/0x80
  lr : rtl83xx_probe+0x1d8/0x3a0
  Call trace:
   gpiod_set_value+0x44/0x80 (P)
   rtl83xx_probe+0x1d8/0x3a0
   realtek_mdio_probe+0x24/0xa0
   mdio_probe+0x38/0x78
   really_probe+0xc4/0x3e0
   __driver_probe_device+0x15c/0x1b8
   driver_probe_device+0xb4/0x120
   __device_attach_driver+0xb8/0x1a0
   bus_for_each_drv+0x88/0xf0
   __device_attach+0xa0/0x1d8
   device_initial_probe+0x54/0x68
   bus_probe_device+0x38/0xa0
   deferred_probe_work_func+0xb8/0x120
   process_one_work+0x184/0x4e8
   worker_thread+0x188/0x308
   kthread+0x130/0x150
   ret_from_fork+0x10/0x20

Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
be used without triggering the warning.

The reset GPIO has been driven with the non-sleeping gpiod_set_value()
since the driver was added in v4.19.  The call has since been refactored
across several files - from realtek-smi.c / realtek-mdio.c into the common
rtl83xx.c module and then into the rtl83xx_reset_assert() and
rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
applies as-is only to kernels that carry those helpers (v6.9+); older
stable kernels need the same gpiod_set_value_cansleep() conversion at the
corresponding open-coded call sites.

Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Cc: <stable@vger.kernel.org> # 6.9.x
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/dsa/realtek/rtl83xx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index 09fd64880232..8121ec12fd8b 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -334,7 +334,7 @@ void rtl83xx_reset_assert(struct realtek_priv *priv)
 			 "Failed to assert the switch reset control: %pe\n",
 			 ERR_PTR(ret));
 
-	gpiod_set_value(priv->reset, true);
+	gpiod_set_value_cansleep(priv->reset, true);
 }
 
 void rtl83xx_reset_deassert(struct realtek_priv *priv)
@@ -347,7 +347,7 @@ void rtl83xx_reset_deassert(struct realtek_priv *priv)
 			 "Failed to deassert the switch reset control: %pe\n",
 			 ERR_PTR(ret));
 
-	gpiod_set_value(priv->reset, false);
+	gpiod_set_value_cansleep(priv->reset, false);
 }
 
 /**
-- 
2.47.3

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Alvin Šipraga]

On Fri, Aug 14, 2026 at 01:01:02PM +0200, Oleksij Rempel wrote:
> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> 
> rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> the probe path, which may sleep and is not timing-critical.  When the
> reset GPIO is provided by a sleeping controller such as an I2C I/O
> expander, gpiod_set_value() warns:
> 
>   WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61
>   Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT)
>   Workqueue: events_unbound deferred_probe_work_func
>   pc : gpiod_set_value+0x44/0x80
>   lr : rtl83xx_probe+0x1d8/0x3a0
>   Call trace:
>    gpiod_set_value+0x44/0x80 (P)
>    rtl83xx_probe+0x1d8/0x3a0
>    realtek_mdio_probe+0x24/0xa0
>    mdio_probe+0x38/0x78
>    really_probe+0xc4/0x3e0
>    __driver_probe_device+0x15c/0x1b8
>    driver_probe_device+0xb4/0x120
>    __device_attach_driver+0xb8/0x1a0
>    bus_for_each_drv+0x88/0xf0
>    __device_attach+0xa0/0x1d8
>    device_initial_probe+0x54/0x68
>    bus_probe_device+0x38/0xa0
>    deferred_probe_work_func+0xb8/0x120
>    process_one_work+0x184/0x4e8
>    worker_thread+0x188/0x308
>    kthread+0x130/0x150
>    ret_from_fork+0x10/0x20
> 
> Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> be used without triggering the warning.
> 
> The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> since the driver was added in v4.19.  The call has since been refactored
> across several files - from realtek-smi.c / realtek-mdio.c into the common
> rtl83xx.c module and then into the rtl83xx_reset_assert() and
> rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> applies as-is only to kernels that carry those helpers (v6.9+); older
> stable kernels need the same gpiod_set_value_cansleep() conversion at the
> corresponding open-coded call sites.
> 
> Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
> Cc: <stable@vger.kernel.org> # 6.9.x
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  drivers/net/dsa/realtek/rtl83xx.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Alvin Šipraga <alvin.sipraga@analog.com>

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Andrew Lunn]

On Fri, Aug 14, 2026 at 01:01:02PM +0200, Oleksij Rempel wrote:
> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> 
> rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> the probe path, which may sleep and is not timing-critical.  When the
> reset GPIO is provided by a sleeping controller such as an I2C I/O
> expander, gpiod_set_value() warns:
> 
> Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> be used without triggering the warning.
> 
> The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> since the driver was added in v4.19.  The call has since been refactored
> across several files - from realtek-smi.c / realtek-mdio.c into the common
> rtl83xx.c module and then into the rtl83xx_reset_assert() and
> rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> applies as-is only to kernels that carry those helpers (v6.9+); older
> stable kernels need the same gpiod_set_value_cansleep() conversion at the
> corresponding open-coded call sites.

This is one of those fuzzy cases. It never worked, so this is not a
regression. Nobody has needed it up until now. So it probably should
be considered a new feature, and merged via net-next.

   Andrew

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Jakub Kicinski]

On Fri, 14 Aug 2026 16:09:04 +0200 Andrew Lunn wrote:
> On Fri, Aug 14, 2026 at 01:01:02PM +0200, Oleksij Rempel wrote:
> > From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> > 
> > rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> > the probe path, which may sleep and is not timing-critical.  When the
> > reset GPIO is provided by a sleeping controller such as an I2C I/O
> > expander, gpiod_set_value() warns:
> > 
> > Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> > be used without triggering the warning.
> > 
> > The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> > since the driver was added in v4.19.  The call has since been refactored
> > across several files - from realtek-smi.c / realtek-mdio.c into the common
> > rtl83xx.c module and then into the rtl83xx_reset_assert() and
> > rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> > applies as-is only to kernels that carry those helpers (v6.9+); older
> > stable kernels need the same gpiod_set_value_cansleep() conversion at the
> > corresponding open-coded call sites.  
> 
> This is one of those fuzzy cases. It never worked, so this is not a
> regression. Nobody has needed it up until now. So it probably should
> be considered a new feature, and merged via net-next.

Sounds like it's a false positive, but it's a WARN, so if it hits on
real platforms -- I think it's a real fix?

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Linus Walleij]

On Fri, Aug 14, 2026 at 1:01 PM Oleksij Rempel <o.rempel@pengutronix.de> wrote:

> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
>
> rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> the probe path, which may sleep and is not timing-critical.  When the
> reset GPIO is provided by a sleeping controller such as an I2C I/O
> expander, gpiod_set_value() warns:
>
>   WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61
>   Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT)
>   Workqueue: events_unbound deferred_probe_work_func
>   pc : gpiod_set_value+0x44/0x80
>   lr : rtl83xx_probe+0x1d8/0x3a0
>   Call trace:
>    gpiod_set_value+0x44/0x80 (P)
>    rtl83xx_probe+0x1d8/0x3a0
>    realtek_mdio_probe+0x24/0xa0
>    mdio_probe+0x38/0x78
>    really_probe+0xc4/0x3e0
>    __driver_probe_device+0x15c/0x1b8
>    driver_probe_device+0xb4/0x120
>    __device_attach_driver+0xb8/0x1a0
>    bus_for_each_drv+0x88/0xf0
>    __device_attach+0xa0/0x1d8
>    device_initial_probe+0x54/0x68
>    bus_probe_device+0x38/0xa0
>    deferred_probe_work_func+0xb8/0x120
>    process_one_work+0x184/0x4e8
>    worker_thread+0x188/0x308
>    kthread+0x130/0x150
>    ret_from_fork+0x10/0x20
>
> Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> be used without triggering the warning.
>
> The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> since the driver was added in v4.19.  The call has since been refactored
> across several files - from realtek-smi.c / realtek-mdio.c into the common
> rtl83xx.c module and then into the rtl83xx_reset_assert() and
> rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> applies as-is only to kernels that carry those helpers (v6.9+); older
> stable kernels need the same gpiod_set_value_cansleep() conversion at the
> corresponding open-coded call sites.
>
> Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
> Cc: <stable@vger.kernel.org> # 6.9.x
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Luiz Angelo Daros de Luca]

> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
>
> rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> the probe path, which may sleep and is not timing-critical.  When the
> reset GPIO is provided by a sleeping controller such as an I2C I/O
> expander, gpiod_set_value() warns:
>
>   WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61
>   Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT)
>   Workqueue: events_unbound deferred_probe_work_func
>   pc : gpiod_set_value+0x44/0x80
>   lr : rtl83xx_probe+0x1d8/0x3a0
>   Call trace:
>    gpiod_set_value+0x44/0x80 (P)
>    rtl83xx_probe+0x1d8/0x3a0
>    realtek_mdio_probe+0x24/0xa0
>    mdio_probe+0x38/0x78
>    really_probe+0xc4/0x3e0
>    __driver_probe_device+0x15c/0x1b8
>    driver_probe_device+0xb4/0x120
>    __device_attach_driver+0xb8/0x1a0
>    bus_for_each_drv+0x88/0xf0
>    __device_attach+0xa0/0x1d8
>    device_initial_probe+0x54/0x68
>    bus_probe_device+0x38/0xa0
>    deferred_probe_work_func+0xb8/0x120
>    process_one_work+0x184/0x4e8
>    worker_thread+0x188/0x308
>    kthread+0x130/0x150
>    ret_from_fork+0x10/0x20
>
> Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> be used without triggering the warning.
>
> The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> since the driver was added in v4.19.  The call has since been refactored
> across several files - from realtek-smi.c / realtek-mdio.c into the common
> rtl83xx.c module and then into the rtl83xx_reset_assert() and
> rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> applies as-is only to kernels that carry those helpers (v6.9+); older
> stable kernels need the same gpiod_set_value_cansleep() conversion at the
> corresponding open-coded call sites.
>
> Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
> Cc: <stable@vger.kernel.org> # 6.9.x
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  drivers/net/dsa/realtek/rtl83xx.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
> index 09fd64880232..8121ec12fd8b 100644
> --- a/drivers/net/dsa/realtek/rtl83xx.c
> +++ b/drivers/net/dsa/realtek/rtl83xx.c
> @@ -334,7 +334,7 @@ void rtl83xx_reset_assert(struct realtek_priv *priv)
>                          "Failed to assert the switch reset control: %pe\n",
>                          ERR_PTR(ret));
>
> -       gpiod_set_value(priv->reset, true);
> +       gpiod_set_value_cansleep(priv->reset, true);
>  }
>
>  void rtl83xx_reset_deassert(struct realtek_priv *priv)
> @@ -347,7 +347,7 @@ void rtl83xx_reset_deassert(struct realtek_priv *priv)
>                          "Failed to deassert the switch reset control: %pe\n",
>                          ERR_PTR(ret));
>
> -       gpiod_set_value(priv->reset, false);
> +       gpiod_set_value_cansleep(priv->reset, false);
>  }
>
>  /**
> --
> 2.47.3
>

Reviewed-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

Regards,

Luiz

Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

[Oleksij Rempel]

On Fri, Aug 14, 2026 at 10:00:14AM -0700, Jakub Kicinski wrote:
> On Fri, 14 Aug 2026 16:09:04 +0200 Andrew Lunn wrote:
> > On Fri, Aug 14, 2026 at 01:01:02PM +0200, Oleksij Rempel wrote:
> > > From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> > > 
> > > rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
> > > the probe path, which may sleep and is not timing-critical.  When the
> > > reset GPIO is provided by a sleeping controller such as an I2C I/O
> > > expander, gpiod_set_value() warns:
> > > 
> > > Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
> > > be used without triggering the warning.
> > > 
> > > The reset GPIO has been driven with the non-sleeping gpiod_set_value()
> > > since the driver was added in v4.19.  The call has since been refactored
> > > across several files - from realtek-smi.c / realtek-mdio.c into the common
> > > rtl83xx.c module and then into the rtl83xx_reset_assert() and
> > > rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
> > > applies as-is only to kernels that carry those helpers (v6.9+); older
> > > stable kernels need the same gpiod_set_value_cansleep() conversion at the
> > > corresponding open-coded call sites.  
> > 
> > This is one of those fuzzy cases. It never worked, so this is not a
> > regression. Nobody has needed it up until now. So it probably should
> > be considered a new feature, and merged via net-next.
> 
> Sounds like it's a false positive, but it's a WARN, so if it hits on
> real platforms -- I think it's a real fix?

We can back port it for related product by our self. Otherwise, the
LLM back port bot from Sasha Levin will do it any way, as soon as it is
taken. no matter as net or net-next. Flip a coin :)

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