* Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
2026-08-14 11:01 [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO Oleksij Rempel
@ 2026-08-14 11:46 ` Alvin Šipraga
2026-08-14 14:09 ` Andrew Lunn
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Alvin Šipraga @ 2026-08-14 11:46 UTC (permalink / raw)
To: Oleksij Rempel
Cc: Linus Walleij, Luiz Angelo Daros de Luca, Andrew Lunn,
Vladimir Oltean, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Ahmad Fatoum, stable, kernel, linux-kernel, netdev
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>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
2026-08-14 11:01 [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO Oleksij Rempel
2026-08-14 11:46 ` Alvin Šipraga
@ 2026-08-14 14:09 ` Andrew Lunn
2026-08-14 17:00 ` Jakub Kicinski
2026-08-14 20:06 ` Linus Walleij
2026-08-14 20:52 ` Luiz Angelo Daros de Luca
3 siblings, 1 reply; 6+ messages in thread
From: Andrew Lunn @ 2026-08-14 14:09 UTC (permalink / raw)
To: Oleksij Rempel
Cc: Linus Walleij, Luiz Angelo Daros de Luca, Vladimir Oltean,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Ahmad Fatoum, stable, kernel, linux-kernel, Alvin Šipraga,
netdev
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
2026-08-14 14:09 ` Andrew Lunn
@ 2026-08-14 17:00 ` Jakub Kicinski
0 siblings, 0 replies; 6+ messages in thread
From: Jakub Kicinski @ 2026-08-14 17:00 UTC (permalink / raw)
To: Andrew Lunn
Cc: Oleksij Rempel, Linus Walleij, Luiz Angelo Daros de Luca,
Vladimir Oltean, David S. Miller, Eric Dumazet, Paolo Abeni,
Ahmad Fatoum, stable, kernel, linux-kernel, Alvin Šipraga,
netdev
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?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
2026-08-14 11:01 [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO Oleksij Rempel
2026-08-14 11:46 ` Alvin Šipraga
2026-08-14 14:09 ` Andrew Lunn
@ 2026-08-14 20:06 ` Linus Walleij
2026-08-14 20:52 ` Luiz Angelo Daros de Luca
3 siblings, 0 replies; 6+ messages in thread
From: Linus Walleij @ 2026-08-14 20:06 UTC (permalink / raw)
To: Oleksij Rempel
Cc: Luiz Angelo Daros de Luca, Andrew Lunn, Vladimir Oltean,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Ahmad Fatoum, stable, kernel, linux-kernel, Alvin Šipraga,
netdev
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
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
2026-08-14 11:01 [PATCH net v1 1/1] net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO Oleksij Rempel
` (2 preceding siblings ...)
2026-08-14 20:06 ` Linus Walleij
@ 2026-08-14 20:52 ` Luiz Angelo Daros de Luca
3 siblings, 0 replies; 6+ messages in thread
From: Luiz Angelo Daros de Luca @ 2026-08-14 20:52 UTC (permalink / raw)
To: Oleksij Rempel
Cc: Linus Walleij, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Ahmad Fatoum, stable,
kernel, linux-kernel, Alvin Šipraga, netdev
> 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
^ permalink raw reply [flat|nested] 6+ messages in thread