Re: [PATCH] ftgmac100: Disable HW checksum generation on AST2500

[Vijay Khemka <vijaykhemka@fb.com>]

On 9/11/19, 7:49 AM, "Joel Stanley" <joel@jms.id.au> wrote:

    Hi Ben,
    
    On Tue, 10 Sep 2019 at 22:05, Florian Fainelli <f.fainelli@gmail.com> wrote:
    >
    > On 9/10/19 2:37 PM, Vijay Khemka wrote:
    > > HW checksum generation is not working for AST2500, specially with IPV6
    > > over NCSI. All TCP packets with IPv6 get dropped. By disabling this
    > > it works perfectly fine with IPV6.
    > >
    > > Verified with IPV6 enabled and can do ssh.
    >
    > How about IPv4, do these packets have problem? If not, can you continue
    > advertising NETIF_F_IP_CSUM but take out NETIF_F_IPV6_CSUM?
    >
    > >
    > > Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
    > > ---
    > >  drivers/net/ethernet/faraday/ftgmac100.c | 5 +++--
    > >  1 file changed, 3 insertions(+), 2 deletions(-)
    > >
    > > diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
    > > index 030fed65393e..591c9725002b 100644
    > > --- a/drivers/net/ethernet/faraday/ftgmac100.c
    > > +++ b/drivers/net/ethernet/faraday/ftgmac100.c
    > > @@ -1839,8 +1839,9 @@ static int ftgmac100_probe(struct platform_device *pdev)
    > >       if (priv->use_ncsi)
    > >               netdev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER;
    > >
    > > -     /* AST2400  doesn't have working HW checksum generation */
    > > -     if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac")))
    > > +     /* AST2400  and AST2500 doesn't have working HW checksum generation */
    > > +     if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
    > > +                of_device_is_compatible(np, "aspeed,ast2500-mac")))
    
    Do you recall under what circumstances we need to disable hardware checksumming?
Mainly, TCP packets over IPV6 getting dropped. After disabling it was working.
    
    Cheers,
    
    Joel
    
    > >               netdev->hw_features &= ~NETIF_F_HW_CSUM;
    > >       if (np && of_get_property(np, "no-hw-checksum", NULL))
    > >               netdev->hw_features &= ~(NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
    > >
    >
    >
    > --
    > Florian