[PATCH RFC net-next 02/10] net: stmmac: rename dev_id to userver

[Jitendra Vegiraju]

On Fri, Apr 10, 2026 at 1:39 AM Russell King (Oracle)
<linux at armlinux.org.uk> wrote:
>
> On Thu, Apr 09, 2026 at 04:07:42PM -0700, Jitendra Vegiraju wrote:
> > Hi Russell,
> >
> > On Wed, Apr 8, 2026 at 2:27 AM Russell King (Oracle)
> > <rmk+kernel at armlinux.org.uk> wrote:
> > >
> > > The Synopsys Databook and several implementation TRMs identify bits
> > > 15:8 of the version register in dwmac v3.xx and v4.xx as "userver".
> > > We even print its value with "User ID". Rather than using "dev_id",
> > > use "userver" instead.
> > >
> > > Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
> > > ---
> > >  drivers/net/ethernet/stmicro/stmmac/hwif.c | 18 +++++++++---------
> > >  1 file changed, 9 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > > index 3774af66db48..830ff816ab4f 100644
> > > --- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > > +++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > > @@ -15,7 +15,7 @@
> > >
> > >  struct stmmac_version {
> > >         u8 snpsver;
> > > -       u8 dev_id;
> > > +       u8 userver;
> > >  };
> > From the XGMAC databook that I have access to bits(15:8) identify the
> > DEVID field of MAC_version register.
> > The userver field is from bits(23:16) of the same register. This is a
> > customer defined field (configured with coreConsultant).
> > Currently stmmac doesn't care about bits(23:16).
>
> Thanks for the additional information.
>
> I don't have any XGMAC documentation, but this indicates that it differs
> between XGMAC and previous cores - GMAC and GMAC4 cores, 15:8 are
> documented as userver, and 31:16 are marked as reserved.
>
> Note that the dev_info() also prints 15:8 as "User ID" not "Device ID".
>
> To confirm, is the XGMAC version register at offset 0x20 ? Later GMAC
> cores moved it to 0x110.
The XGMAC version register is at offset 0x110.

>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
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