ACK/cmnt: [PATCH 0/1][SRU][H/OEM-5.13/OEM-5.14/U] UBUNTU: SAUCE: Fix invalid MAC address after hotplug tbt dock

[Kai-Heng Feng]

On Fri, Sep 10, 2021 at 1:59 PM Aaron Ma <aaron.ma at canonical.com> wrote:
>
>
> On 9/10/21 1:12 PM, Kai-Heng Feng wrote:
> > On Wed, Sep 8, 2021 at 8:40 PM Aaron Ma <aaron.ma at canonical.com> wrote:
> >>
> >>
> >> On 9/8/21 8:06 PM, Tim Gardner wrote:
> >>>
> >>> Ick. It seems like there ought to be a more deterministic way to note when the MAC address has been copied. Why not a loop that does an msleep(1) until the MAC is address is updated or 600 msec elapses ?
> >>
> >> The MAC address of dock will read out at first, after 600 msec the MAC in BIOS will be updated.
> >> Driver doesn't know which one is the right MAC address. This allows enough time for hardware to update the
> >
> > According to [1], there _can_ be IRQ raised when MAC update is
> > completed. So it's a good idea to check it.
> > If there's no IRQ from FW at current stage, then this is an unpleasant
> > but necessary workaround.
> >
> > [1] https://lore.kernel.org/netdev/20daa122-aaec-0c6b-23f5-d2be2fcab1e9@intel.com/
> >
>
> In current fw, no such irq.

Since it's confirmed there's no IRQ raised on MAC update completion,
it's plausible to use this workaround.

Acked-by: Kai-Heng Feng <kai.heng.feng at canonical.com>

>
> Aaron
>
> > Kai-Heng
> >
> >>
> >> MAC address.
> >>
> >> Aaron
> >>
> >>>
> >>> On 9/8/21 2:49 AM, Aaron Ma wrote:
> >>>> BugLink: https://bugs.launchpad.net/bugs/1942999
> >>>>
> >>>> SRU justification:
> >>>>
> >>>> [Impact]
> >>>> igc driver can not connect to network after re-plugin thunderbolt dock
> >>>> when
> >>>> MAC passthrough enabled in BIOS.
> >>>>
> >>>> [Fix]
> >>>> Wait for the MAC copy of BIOS when enabled MAC passthrough.
> >>>> Intel engineer wants a different solution and promise to discuss with
> >>>> firmware engineer.
> >>>> Due to the schedule, made this as a short term solution to fix the
> >>>> issue, and wait for the other
> >>>> fix from Intel.
> >>>>
> >>>> [Test]
> >>>> Verified on hardware, after hotplug the thunderbolt cable,
> >>>> Ethernet works fine.
> >>>>
> >>>> [Where problems could occur]
> >>>> It may break the igc driver.
> >>>>
> >>>> Aaron Ma (1):
> >>>>     UBUNTU: SAUCE: igc: wait for the MAC copy when enabled MAC passthrough
> >>>>
> >>>>    drivers/net/ethernet/intel/igc/igc_main.c | 3 +++
> >>>>    1 file changed, 3 insertions(+)
> >>>>
> >>>
> >>
> >> --
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