[J/OEM-5.17/U][PATCH 1/1] UBUNTU: SAUCE: igc: wait for the MAC copy when enabled MAC passthrough

[Aaron Ma]

On 8/4/22 14:37, Andrea Righi wrote:
> On Wed, Aug 03, 2022 at 03:55:53PM +0800, Aaron Ma wrote:
>> BugLink: https://bugs.launchpad.net/bugs/1942999
>>
>> Such as dock hot plug event when runtime, for hardware implementation,
>> the MAC copy takes less than one second when BIOS enabled MAC passthrough.
>> After test on Lenovo TBT4 dock, 600ms is enough to update the
>> MAC address.
>> Otherwise ethernet fails to work.
>>
>> Link: https://lore.kernel.org/lkml/20210702045120.22855-2-aaron.ma@canonical.com/
>> Signed-off-by: Aaron Ma <aaron.ma at canonical.com>
>> ---
>>   drivers/net/ethernet/intel/igc/igc_main.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
>> index f99819fc559d9..634cfdc203203 100644
>> --- a/drivers/net/ethernet/intel/igc/igc_main.c
>> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
>> @@ -6323,6 +6323,9 @@ static int igc_probe(struct pci_dev *pdev,
>>   	memcpy(&hw->mac.ops, ei->mac_ops, sizeof(hw->mac.ops));
>>   	memcpy(&hw->phy.ops, ei->phy_ops, sizeof(hw->phy.ops));
>>   
>> +	if (pci_is_thunderbolt_attached(pdev))
>> +		msleep(600);
>> +
> Unconditional sleeps are always unpredictable and a bit scary... isn't
> there a more reliable way to detect when the MAC address is updated?
> Like an interrupt, reading back from a register or somthing similar?

That's the ideal way, but I discussed with Intel, there is no such interrupts.
In the datasheet, the I225 Windows driver implementation is to wait for 1 second.

Regards,
Aaron

> Thanks,
> -Andrea
>
>>   	/* Initialize skew-specific constants */
>>   	err = ei->get_invariants(hw);
>>   	if (err)
>> -- 
>> 2.37.1
>>
>>
>> -- 
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