Re: [PATCH] net/cadence_gem: Set PHY autonegotiation restart status

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 11/5/19 12:31 PM, Linus Ziegert wrote:
> Am Mo., 4. Nov. 2019 um 23:50 Uhr schrieb Alistair Francis 
> <alistair23@gmail.com <mailto:alistair23@gmail.com>>:
>  >
>  > On Mon, Nov 4, 2019 at 2:02 PM <linus.ziegert@holoplot.com 
> <mailto:linus.ziegert@holoplot.com>> wrote:
>  > >
>  > > From: Linus Ziegert <linus.ziegert+qemu@holoplot.com 
> <mailto:linus.ziegert%2Bqemu@holoplot.com>>
>  > >
>  > > The Linux kernel PHY driver sets AN_RESTART in the BMCR of the
>  > > PHY when autonegotiation is started.
>  > > Recently the kernel started to read back the PHY's AN_RESTART
>  > > bit and now checks whether the autonegotiation is complete and
>  > > the bit was cleared [1]. Otherwise the link status is down.
>  > >
>  > > The emulated PHY needs to clear AN_RESTART immediately to inform
>  > > the kernel driver about the completion of autonegotiation phase.
>  > >
>  > > [1] 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c36757eb9dee
>  > >
>  > > Signed-off-by: Linus Ziegert <linus.ziegert+qemu@holoplot.com 
> <mailto:linus.ziegert%2Bqemu@holoplot.com>>
>  >
>  > Reviewed-by: Alistair Francis <alistair.francis@wdc.com 
> <mailto:alistair.francis@wdc.com>>
> 
> I consider this stable material. Applies cleanly to all versions 
> starting from v1.5.0.

Too bad this wasn't Cc'ed to qemu-stable@nongnu.org and missed 4.1.1 
stable release.

Jason: ping?

>  > Alistair
>  >
>  > > ---
>  > >  hw/net/cadence_gem.c | 9 +++++----
>  > >  1 file changed, 5 insertions(+), 4 deletions(-)
>  > >
>  > > diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
>  > > index 7f9cb5ab95..b8be73dc55 100644
>  > > --- a/hw/net/cadence_gem.c
>  > > +++ b/hw/net/cadence_gem.c
>  > > @@ -271,9 +271,10 @@
>  > >  #define PHY_REG_EXT_PHYSPCFC_ST   27
>  > >  #define PHY_REG_CABLE_DIAG   28
>  > >
>  > > -#define PHY_REG_CONTROL_RST  0x8000
>  > > -#define PHY_REG_CONTROL_LOOP 0x4000
>  > > -#define PHY_REG_CONTROL_ANEG 0x1000
>  > > +#define PHY_REG_CONTROL_RST       0x8000
>  > > +#define PHY_REG_CONTROL_LOOP      0x4000
>  > > +#define PHY_REG_CONTROL_ANEG      0x1000
>  > > +#define PHY_REG_CONTROL_ANRESTART 0x0200
>  > >
>  > >  #define PHY_REG_STATUS_LINK     0x0004
>  > >  #define PHY_REG_STATUS_ANEGCMPL 0x0020
>  > > @@ -1345,7 +1346,7 @@ static void gem_phy_write(CadenceGEMState *s, 
> unsigned reg_num, uint16_t val)
>  > >          }
>  > >          if (val & PHY_REG_CONTROL_ANEG) {
>  > >              /* Complete autonegotiation immediately */
>  > > -            val &= ~PHY_REG_CONTROL_ANEG;
>  > > +            val &= ~(PHY_REG_CONTROL_ANEG | 
> PHY_REG_CONTROL_ANRESTART);
>  > >              s->phy_regs[PHY_REG_STATUS] |= PHY_REG_STATUS_ANEGCMPL;
>  > >          }
>  > >          if (val & PHY_REG_CONTROL_LOOP) {
>  > > --
>  > > 2.21.0
>  > >
>  > >