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Subject: Re: [Intel-wired-lan] [PATCH 2/2] igc: wait for the MAC copy when
 enabled MAC passthrough
To:     Aaron Ma <aaron.ma@canonical.com>, jesse.brandeburg@intel.com,
        anthony.l.nguyen@intel.com, davem@davemloft.net, kuba@kernel.org,
        intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        "Edri, Michael" <michael.edri@intel.com>,
        "Ruinskiy, Dima" <dima.ruinskiy@intel.com>,
        "Neftin, Sasha" <sasha.neftin@intel.com>
References: <20210702045120.22855-1-aaron.ma@canonical.com>
 <20210702045120.22855-2-aaron.ma@canonical.com>
From:   "Neftin, Sasha" <sasha.neftin@intel.com>
Message-ID: <613e2106-940a-49ed-6621-0bb00bc7dca5@intel.com>
Date:   Sun, 4 Jul 2021 08:36:53 +0300
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On 7/2/2021 07:51, Aaron Ma wrote:
> 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.
> 
> Signed-off-by: Aaron Ma <aaron.ma@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 606b72cb6193..c8bc5f089255 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -5468,6 +5468,9 @@ 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);
I believe it is a bit fragile. I would recommend here look for another 
indication instead of delay. Can we poll for a 'pci_channel_io_normal' 
state? (igc->pdev->error_state == pci_channel_io_normal)
> +
>   	/* Initialize skew-specific constants */
>   	err = ei->get_invariants(hw);
>   	if (err)
> 
Thanks Aaron,
sasha