2021-03-16 09:46:36

by Wong, Vee Khee

[permalink] [raw]
Subject: [PATCH net-next 1/1] net: phy: fix invalid phy id when probe using C22

When using Clause-22 to probe for PHY devices such as the Marvell
88E2110, PHY ID with value 0 is read from the MII PHYID registers
which caused the PHY framework failed to attach the Marvell PHY
driver.

Fixed this by adding a check of PHY ID equals to all zeroes.

Cc: [email protected]
Reviewed-by: Voon Weifeng <[email protected]>
Signed-off-by: Wong Vee Khee <[email protected]>
---
drivers/net/phy/phy_device.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index a009d1769b08..f1afc00fcba2 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -820,8 +820,8 @@ static int get_phy_c22_id(struct mii_bus *bus, int addr, u32 *phy_id)

*phy_id |= phy_reg;

- /* If the phy_id is mostly Fs, there is no device there */
- if ((*phy_id & 0x1fffffff) == 0x1fffffff)
+ /* If the phy_id is mostly Fs or all zeroes, there is no device there */
+ if (((*phy_id & 0x1fffffff) == 0x1fffffff) || (*phy_id == 0))
return -ENODEV;

return 0;
--
2.25.1


2021-03-17 08:19:24

by Heiner Kallweit

[permalink] [raw]
Subject: Re: [PATCH net-next 1/1] net: phy: fix invalid phy id when probe using C22

On 16.03.2021 09:57, Wong Vee Khee wrote:
> When using Clause-22 to probe for PHY devices such as the Marvell
> 88E2110, PHY ID with value 0 is read from the MII PHYID registers
> which caused the PHY framework failed to attach the Marvell PHY
> driver.
>

The issue occurs with a MAC driver that sets MDIO bus capability
flag MDIOBUS_C22_C45, like stmmac? Or what is the affected MAC
driver?

And if you state it's a fix, a Fixes tag would be needed.

> Fixed this by adding a check of PHY ID equals to all zeroes.
>
> Cc: [email protected]
> Reviewed-by: Voon Weifeng <[email protected]>
> Signed-off-by: Wong Vee Khee <[email protected]>
> ---
> drivers/net/phy/phy_device.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index a009d1769b08..f1afc00fcba2 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -820,8 +820,8 @@ static int get_phy_c22_id(struct mii_bus *bus, int addr, u32 *phy_id)
>
> *phy_id |= phy_reg;
>
> - /* If the phy_id is mostly Fs, there is no device there */
> - if ((*phy_id & 0x1fffffff) == 0x1fffffff)
> + /* If the phy_id is mostly Fs or all zeroes, there is no device there */
> + if (((*phy_id & 0x1fffffff) == 0x1fffffff) || (*phy_id == 0))
> return -ENODEV;
>
> return 0;
>

2021-03-18 06:56:11

by Wong, Vee Khee

[permalink] [raw]
Subject: RE: [PATCH net-next 1/1] net: phy: fix invalid phy id when probe using C22

> -----Original Message-----
> From: Heiner Kallweit <[email protected]>
> Sent: Wednesday, March 17, 2021 4:15 PM
> To: Wong, Vee Khee <[email protected]>; Andrew Lunn
> <[email protected]>; Russell King <[email protected]>; David S . Miller
> <[email protected]>; Jakub Kicinski <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; Voon Weifeng <[email protected]>; Ong,
> Boon Leong <[email protected]>
> Subject: Re: [PATCH net-next 1/1] net: phy: fix invalid phy id when probe
> using C22
>
> On 16.03.2021 09:57, Wong Vee Khee wrote:
> > When using Clause-22 to probe for PHY devices such as the Marvell
> > 88E2110, PHY ID with value 0 is read from the MII PHYID registers
> > which caused the PHY framework failed to attach the Marvell PHY
> > driver.
> >
>
> The issue occurs with a MAC driver that sets MDIO bus capability
> flag MDIOBUS_C22_C45, like stmmac? Or what is the affected MAC
> driver?
>

Yes, you are right. This issue is seen when MarvellE2110 is used with
the STMMAC.

> And if you state it's a fix, a Fixes tag would be needed.
>

Noted. Will send a v2 and marked for net.

> > Fixed this by adding a check of PHY ID equals to all zeroes.
> >
> > Cc: [email protected]
> > Reviewed-by: Voon Weifeng <[email protected]>
> > Signed-off-by: Wong Vee Khee <[email protected]>
> > ---
> > drivers/net/phy/phy_device.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> > index a009d1769b08..f1afc00fcba2 100644
> > --- a/drivers/net/phy/phy_device.c
> > +++ b/drivers/net/phy/phy_device.c
> > @@ -820,8 +820,8 @@ static int get_phy_c22_id(struct mii_bus *bus, int
> addr, u32 *phy_id)
> >
> > *phy_id |= phy_reg;
> >
> > - /* If the phy_id is mostly Fs, there is no device there */
> > - if ((*phy_id & 0x1fffffff) == 0x1fffffff)
> > + /* If the phy_id is mostly Fs or all zeroes, there is no device there */
> > + if (((*phy_id & 0x1fffffff) == 0x1fffffff) || (*phy_id == 0))
> > return -ENODEV;
> >
> > return 0;
> >