Messages in this thread Patch in this message | | | From | Vijay Khemka <> | Subject | Re: [PATCH v2] ftgmac100: Disable HW checksum generation on AST2500 | Date | Thu, 17 Oct 2019 22:01:48 +0000 |
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On 10/16/19, 6:29 PM, "Benjamin Herrenschmidt" <benh@kernel.crashing.org> wrote:
On Fri, 2019-10-11 at 14:30 -0700, 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. As it works for IPV4 so enabled > hw checksum back for IPV4. > > Verified with IPV6 enabled and can do ssh. So while this probably works, I don't think this is the right approach, at least according to the comments in skbuff.h
This is not a matter of unsupported csum, it is broken hw csum. That's why we disable hw checksum. My guess is once we disable Hw checksum, it will use sw checksum. So I am just disabling hw Checksum. The driver should have handled unsupported csum via SW fallback already in ftgmac100_prep_tx_csum() Can you check why this didn't work for you ? Cheers, Ben. > Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> > --- > Changes since v1: > Enabled IPV4 hw checksum generation as it works for IPV4. > > drivers/net/ethernet/faraday/ftgmac100.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/faraday/ftgmac100.c > b/drivers/net/ethernet/faraday/ftgmac100.c > index 030fed65393e..0255a28d2958 100644 > --- a/drivers/net/ethernet/faraday/ftgmac100.c > +++ b/drivers/net/ethernet/faraday/ftgmac100.c > @@ -1842,8 +1842,19 @@ static int ftgmac100_probe(struct > platform_device *pdev) > /* AST2400 doesn't have working HW checksum generation */ > if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac"))) > netdev->hw_features &= ~NETIF_F_HW_CSUM; > + > + /* AST2500 doesn't have working HW checksum generation for IPV6 > + * but it works for IPV4, so disabling hw checksum and enabling > + * it for only IPV4. > + */ > + if (np && (of_device_is_compatible(np, "aspeed,ast2500-mac"))) > { > + netdev->hw_features &= ~NETIF_F_HW_CSUM; > + netdev->hw_features |= NETIF_F_IP_CSUM; > + } > + > if (np && of_get_property(np, "no-hw-checksum", NULL)) > - netdev->hw_features &= ~(NETIF_F_HW_CSUM | > NETIF_F_RXCSUM); > + netdev->hw_features &= ~(NETIF_F_HW_CSUM | > NETIF_F_RXCSUM > + | NETIF_F_IP_CSUM); > netdev->features |= netdev->hw_features; > > /* register network device */
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