diff mbox series

[2/2] net: eth-phy: prevent undesired de-assertion of phy-reset on request

Message ID 20220301201502.28026-3-tharvey@gateworks.com
State Accepted
Commit f3409d7ae6127b6aa33ec9cdb63808745ed4b56e
Delegated to: Ramon Fried
Headers show
Series prevent undesired de-assertion of phy-reset | expand

Commit Message

Tim Harvey March 1, 2022, 8:15 p.m. UTC
When gpio_request_by_name allocates a gpio output it by default will
de-assert the gpio which for phy-reset will take the PHY out of reset.
As this occurs before eth_phy_reset is called to assert the reset
line it can cause undesired affects if reset timings are not properly
met.

Configure the gpio with GPIOD_IS_OUT_ACTIVE so that reset is kept active
(reset asserted) to avoid this.

Cc: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 drivers/net/eth-phy-uclass.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Joe Hershberger March 1, 2022, 8:38 p.m. UTC | #1
On Tue, Mar 1, 2022 at 2:15 PM Tim Harvey <tharvey@gateworks.com> wrote:
>
> When gpio_request_by_name allocates a gpio output it by default will
> de-assert the gpio which for phy-reset will take the PHY out of reset.
> As this occurs before eth_phy_reset is called to assert the reset
> line it can cause undesired affects if reset timings are not properly
> met.
>
> Configure the gpio with GPIOD_IS_OUT_ACTIVE so that reset is kept active
> (reset asserted) to avoid this.
>
> Cc: Sean Anderson <sean.anderson@seco.com>
> Signed-off-by: Tim Harvey <tharvey@gateworks.com>

Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Ramon Fried March 3, 2022, 7:55 a.m. UTC | #2
On Tue, Mar 1, 2022 at 10:38 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>
> On Tue, Mar 1, 2022 at 2:15 PM Tim Harvey <tharvey@gateworks.com> wrote:
> >
> > When gpio_request_by_name allocates a gpio output it by default will
> > de-assert the gpio which for phy-reset will take the PHY out of reset.
> > As this occurs before eth_phy_reset is called to assert the reset
> > line it can cause undesired affects if reset timings are not properly
> > met.
> >
> > Configure the gpio with GPIOD_IS_OUT_ACTIVE so that reset is kept active
> > (reset asserted) to avoid this.
> >
> > Cc: Sean Anderson <sean.anderson@seco.com>
> > Signed-off-by: Tim Harvey <tharvey@gateworks.com>
>
> Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Ramon Fried April 10, 2022, 5:05 a.m. UTC | #3
On Thu, Mar 3, 2022 at 9:55 AM Ramon Fried <rfried.dev@gmail.com> wrote:
>
> On Tue, Mar 1, 2022 at 10:38 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >
> > On Tue, Mar 1, 2022 at 2:15 PM Tim Harvey <tharvey@gateworks.com> wrote:
> > >
> > > When gpio_request_by_name allocates a gpio output it by default will
> > > de-assert the gpio which for phy-reset will take the PHY out of reset.
> > > As this occurs before eth_phy_reset is called to assert the reset
> > > line it can cause undesired affects if reset timings are not properly
> > > met.
> > >
> > > Configure the gpio with GPIOD_IS_OUT_ACTIVE so that reset is kept active
> > > (reset asserted) to avoid this.
> > >
> > > Cc: Sean Anderson <sean.anderson@seco.com>
> > > Signed-off-by: Tim Harvey <tharvey@gateworks.com>
> >
> > Acked-by: Joe Hershberger <joe.hershberger@ni.com>
> Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Applied to u-boot-net/next
Thanks,
Ramon
diff mbox series

Patch

diff --git a/drivers/net/eth-phy-uclass.c b/drivers/net/eth-phy-uclass.c
index 1f285f7afd20..27b77444a0c5 100644
--- a/drivers/net/eth-phy-uclass.c
+++ b/drivers/net/eth-phy-uclass.c
@@ -137,7 +137,7 @@  static int eth_phy_of_to_plat(struct udevice *dev)
 	/* search "reset-gpios" in phy node */
 	ret = gpio_request_by_name(dev, "reset-gpios", 0,
 				   &uc_priv->reset_gpio,
-				   GPIOD_IS_OUT);
+				   GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
 	if (ret && ret != -ENOENT)
 		return ret;