RE: [PATCH net-next v4 2/2] ixgbe: use mii_bus to handle MII related ioctls

[Bowers, AndrewX]

> -Original Message-
> From: Intel-wired-lan [mailto:intel-wired-lan-boun...@osuosl.org] On
> Behalf Of Steve Douthit
> Sent: Monday, December 3, 2018 12:15 PM
> To: Kirsher, Jeffrey T 
> Cc: Andrew Lunn ; Florian Fainelli ;
> netdev@vger.kernel.org; intel-wired-...@lists.osuosl.org; David S. Miller
> 
> Subject: [Intel-wired-lan] [PATCH net-next v4 2/2] ixgbe: use mii_bus to
> handle MII related ioctls
> 
> Use the mii_bus callbacks to address the entire clause 22/45 address space.
> Enables userspace to poke switch registers instead of a single PHY address.
> 
> The ixgbe firmware may be polling PHYs in a way that is not protected by the
> mii_bus lock.  This isn't new behavior, but as Andrew Lunn pointed out there
> are more addresses available for conflicts.
> 
> Signed-off-by: Stephen Douthit 
> Reviewed-by: Andrew Lunn 
> Reviewed-by: Florian Fainelli 
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 18 ++
>  1 file changed, 18 insertions(+)

Tested-by: Andrew Bowers 

[PATCH net-next v4 2/2] ixgbe: use mii_bus to handle MII related ioctls

[Steve Douthit]

Use the mii_bus callbacks to address the entire clause 22/45 address
space.  Enables userspace to poke switch registers instead of a single
PHY address.

The ixgbe firmware may be polling PHYs in a way that is not protected by
the mii_bus lock.  This isn't new behavior, but as Andrew Lunn pointed
out there are more addresses available for conflicts.

Signed-off-by: Stephen Douthit 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c 
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index b7907674c565..caa64afdedfb 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8790,6 +8790,15 @@ ixgbe_mdio_read(struct net_device *netdev, int prtad, 
int devad, u16 addr)
u16 value;
int rc;
 
+   if (adapter->mii_bus) {
+   int regnum = addr;
+
+   if (devad != MDIO_DEVAD_NONE)
+   regnum |= (devad << 16) | MII_ADDR_C45;
+
+   return mdiobus_read(adapter->mii_bus, prtad, regnum);
+   }
+
if (prtad != hw->phy.mdio.prtad)
return -EINVAL;
rc = hw->phy.ops.read_reg(hw, addr, devad, );
@@ -8804,6 +8813,15 @@ static int ixgbe_mdio_write(struct net_device *netdev, 
int prtad, int devad,
struct ixgbe_adapter *adapter = netdev_priv(netdev);
struct ixgbe_hw *hw = >hw;
 
+   if (adapter->mii_bus) {
+   int regnum = addr;
+
+   if (devad != MDIO_DEVAD_NONE)
+   regnum |= (devad << 16) | MII_ADDR_C45;
+
+   return mdiobus_write(adapter->mii_bus, prtad, regnum, value);
+   }
+
if (prtad != hw->phy.mdio.prtad)
return -EINVAL;
return hw->phy.ops.write_reg(hw, addr, devad, value);
-- 
2.17.2