In case of asix_ax88772a_link_change_notify() workaround, we run soft
reset which will automatically clear MII_ADVERTISE configuration. The
PHYlib framework do not know about changed configuration state of the
PHY, so we need to save and restore all needed configuration registers.
Fixes: dde258469257 ("net: usb/phy: asix: add support for ax88772A/C PHYs")
Signed-off-by: Oleksij Rempel <[email protected]>
---
drivers/net/phy/ax88796b.c | 37 ++++++++++++++++++++++++++++++++++++-
1 file changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/ax88796b.c b/drivers/net/phy/ax88796b.c
index 457896337505..6971d0196917 100644
--- a/drivers/net/phy/ax88796b.c
+++ b/drivers/net/phy/ax88796b.c
@@ -18,6 +18,11 @@ MODULE_DESCRIPTION("Asix PHY driver");
MODULE_AUTHOR("Michael Schmitz <[email protected]>");
MODULE_LICENSE("GPL");
+struct asix_context {
+ u16 bmcr;
+ u16 advertise;
+};
+
/**
* asix_soft_reset - software reset the PHY via BMCR_RESET bit
* @phydev: target phy_device struct
@@ -83,13 +88,43 @@ static int asix_ax88772a_read_status(struct phy_device *phydev)
return 0;
}
+/* save relevant PHY registers to private copy */
+static void asix_context_save(struct phy_device *phydev,
+ struct asix_context *context)
+{
+ context->bmcr = phy_read(phydev, MII_BMCR);
+ context->advertise = phy_read(phydev, MII_ADVERTISE);
+}
+
+/* restore relevant PHY registers from private copy */
+static void asix_context_restore(struct phy_device *phydev,
+ const struct asix_context *context)
+{
+ u16 bmcr = context->bmcr;
+
+ phy_write(phydev, MII_ADVERTISE, context->advertise);
+
+ /* after all settings are restored, restart autoneg */
+ if (phydev->autoneg == AUTONEG_ENABLE)
+ bmcr |= BMCR_ANRESTART;
+
+ phy_write(phydev, MII_BMCR, bmcr);
+}
+
static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
{
/* Reset PHY, otherwise MII_LPA will provide outdated information.
* This issue is reproducible only with some link partner PHYs
*/
- if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
+ if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) {
+ struct asix_context context;
+
+ asix_context_save(phydev, &context);
+
phydev->drv->soft_reset(phydev);
+
+ asix_context_restore(phydev, &context);
+ }
}
static struct phy_driver asix_driver[] = {
--
2.30.2
I forgot to add PHY maintainers. CCing Andrew and Heiner.
On Fri, Jun 24, 2022 at 09:55:58AM +0200, Oleksij Rempel wrote:
> In case of asix_ax88772a_link_change_notify() workaround, we run soft
> reset which will automatically clear MII_ADVERTISE configuration. The
> PHYlib framework do not know about changed configuration state of the
> PHY, so we need to save and restore all needed configuration registers.
>
> Fixes: dde258469257 ("net: usb/phy: asix: add support for ax88772A/C PHYs")
> Signed-off-by: Oleksij Rempel <[email protected]>
> ---
> drivers/net/phy/ax88796b.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/phy/ax88796b.c b/drivers/net/phy/ax88796b.c
> index 457896337505..6971d0196917 100644
> --- a/drivers/net/phy/ax88796b.c
> +++ b/drivers/net/phy/ax88796b.c
> @@ -18,6 +18,11 @@ MODULE_DESCRIPTION("Asix PHY driver");
> MODULE_AUTHOR("Michael Schmitz <[email protected]>");
> MODULE_LICENSE("GPL");
>
> +struct asix_context {
> + u16 bmcr;
> + u16 advertise;
> +};
> +
> /**
> * asix_soft_reset - software reset the PHY via BMCR_RESET bit
> * @phydev: target phy_device struct
> @@ -83,13 +88,43 @@ static int asix_ax88772a_read_status(struct phy_device *phydev)
> return 0;
> }
>
> +/* save relevant PHY registers to private copy */
> +static void asix_context_save(struct phy_device *phydev,
> + struct asix_context *context)
> +{
> + context->bmcr = phy_read(phydev, MII_BMCR);
> + context->advertise = phy_read(phydev, MII_ADVERTISE);
> +}
> +
> +/* restore relevant PHY registers from private copy */
> +static void asix_context_restore(struct phy_device *phydev,
> + const struct asix_context *context)
> +{
> + u16 bmcr = context->bmcr;
> +
> + phy_write(phydev, MII_ADVERTISE, context->advertise);
> +
> + /* after all settings are restored, restart autoneg */
> + if (phydev->autoneg == AUTONEG_ENABLE)
> + bmcr |= BMCR_ANRESTART;
> +
> + phy_write(phydev, MII_BMCR, bmcr);
> +}
> +
> static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
> {
> /* Reset PHY, otherwise MII_LPA will provide outdated information.
> * This issue is reproducible only with some link partner PHYs
> */
> - if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
> + if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) {
> + struct asix_context context;
> +
> + asix_context_save(phydev, &context);
> +
> phydev->drv->soft_reset(phydev);
> +
> + asix_context_restore(phydev, &context);
> + }
> }
>
> static struct phy_driver asix_driver[] = {
> --
> 2.30.2
>
>
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Fri, Jun 24, 2022 at 09:55:58AM +0200, Oleksij Rempel wrote:
> In case of asix_ax88772a_link_change_notify() workaround, we run soft
> reset which will automatically clear MII_ADVERTISE configuration. The
> PHYlib framework do not know about changed configuration state of the
> PHY, so we need to save and restore all needed configuration registers.
[...]
> static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
> {
> /* Reset PHY, otherwise MII_LPA will provide outdated information.
> * This issue is reproducible only with some link partner PHYs
> */
> - if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
> + if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) {
> + struct asix_context context;
> +
> + asix_context_save(phydev, &context);
> +
> phydev->drv->soft_reset(phydev);
> +
> + asix_context_restore(phydev, &context);
> + }
> }
Hm, how about just calling phy_init_hw()? That will perform a
->soft_reset() and also restore the configuration, including
interrupts (which the above does not, but I guess that's
irrelevant as long as the driver uses polling).
Does phy_init_hw() do too much or too little compared to the above
and is hence not a viable solution?
Thanks,
Lukas
On Sat, Jun 25, 2022 at 09:17:31AM +0200, Lukas Wunner wrote:
> On Fri, Jun 24, 2022 at 09:55:58AM +0200, Oleksij Rempel wrote:
> > In case of asix_ax88772a_link_change_notify() workaround, we run soft
> > reset which will automatically clear MII_ADVERTISE configuration. The
> > PHYlib framework do not know about changed configuration state of the
> > PHY, so we need to save and restore all needed configuration registers.
> [...]
> > static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
> > {
> > /* Reset PHY, otherwise MII_LPA will provide outdated information.
> > * This issue is reproducible only with some link partner PHYs
> > */
> > - if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
> > + if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) {
> > + struct asix_context context;
> > +
> > + asix_context_save(phydev, &context);
> > +
> > phydev->drv->soft_reset(phydev);
> > +
> > + asix_context_restore(phydev, &context);
> > + }
> > }
>
> Hm, how about just calling phy_init_hw()? That will perform a
> ->soft_reset() and also restore the configuration, including
> interrupts (which the above does not, but I guess that's
> irrelevant as long as the driver uses polling).
>
> Does phy_init_hw() do too much or too little compared to the above
> and is hence not a viable solution?
at803x.c has:
/* After changing the smart speed settings, we need to perform a
* software reset, use phy_init_hw() to make sure we set the
* reapply any values which might got lost during software reset.
*/
if (ret == 1)
ret = phy_init_hw(phydev);
Andrew
On Sun, Jun 26, 2022 at 10:58:24AM +0200, Andrew Lunn wrote:
> On Sat, Jun 25, 2022 at 09:17:31AM +0200, Lukas Wunner wrote:
> > On Fri, Jun 24, 2022 at 09:55:58AM +0200, Oleksij Rempel wrote:
> > > In case of asix_ax88772a_link_change_notify() workaround, we run soft
> > > reset which will automatically clear MII_ADVERTISE configuration. The
> > > PHYlib framework do not know about changed configuration state of the
> > > PHY, so we need to save and restore all needed configuration registers.
> > [...]
> > > static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
> > > {
> > > /* Reset PHY, otherwise MII_LPA will provide outdated information.
> > > * This issue is reproducible only with some link partner PHYs
> > > */
> > > - if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
> > > + if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) {
> > > + struct asix_context context;
> > > +
> > > + asix_context_save(phydev, &context);
> > > +
> > > phydev->drv->soft_reset(phydev);
> > > +
> > > + asix_context_restore(phydev, &context);
> > > + }
> > > }
> >
> > Hm, how about just calling phy_init_hw()? That will perform a
> > ->soft_reset() and also restore the configuration, including
> > interrupts (which the above does not, but I guess that's
> > irrelevant as long as the driver uses polling).
> >
> > Does phy_init_hw() do too much or too little compared to the above
> > and is hence not a viable solution?
>
>
> at803x.c has:
>
> /* After changing the smart speed settings, we need to perform a
> * software reset, use phy_init_hw() to make sure we set the
> * reapply any values which might got lost during software reset.
> */
> if (ret == 1)
> ret = phy_init_hw(phydev);
>
Hm, this is not enough to restore/reconfigure advertisement register.
Should I change PHY state to UP and trigger the state machine?
Regards,
Oleksij
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |