[Intel-wired-lan] [PATCH 2/2] igc: wait for the MAC copy when enabled MAC passthrough
dima.ruinskiy at intel.com
Wed Jul 14 09:13:25 UTC 2021
Hello, Aaron, Sasha,
On 13/07/2021 16:45, Aaron Ma wrote:
> On 7/8/21 12:24 PM, Neftin, Sasha wrote:
>> I would to like suggest checking the following direction:
>> 1. principal question: can we update the netdev device address after
>> it is already set during probe? I meant perform another:
>> memcpy(netdev->dev_addr, hw->mac.addr, netdev->addr_len) up to demand
> Updating MAC addr may work.
> Even at the end of probe, it still got the wrong MAC address, delay is
> still needed.
>> 2. We need to work with Intel's firmware engineer/group and define the
>> message/event: MAC addressis changed and should be updated.
>> As I know MNG FW updates shadow registers. Since shadow registers are
>> different from RAL/RAH registers - it could be a notification that the
>> MAC address changed. Let's check it.
There is an interrupt which the FW can issue to the driver to indicate
that MAC address has been changed. At that point the driver can update
the MAC in its internal structures.
The important question is - is there away to update the OS structures at
that point so that the MAC address change propagates through all the
network stack. Some network stacks do not support such an update, except
during device initialization (probe), so in such environments a delay is
the only workaround, and it is a problematic one as we know.
If we find a mechanism by which the device driver can tell the Linux
network stack - "My MAC address has changed; please update it", we can
implement it differently, and not need this delay. Who can help us with
Intel Israel (74) Limited
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