Re: [PATCH] ftgmac100: Disable HW checksum generation on AST2500
From: Vijay Khemka
Date: Wed Sep 11 2019 - 14:31:51 EST
ïOn 9/10/19, 4:08 PM, "Linux-aspeed on behalf of Vijay Khemka" <linux-aspeed-bounces+vijaykhemka=fb.com@xxxxxxxxxxxxxxxx on behalf of vijaykhemka@xxxxxx> wrote:
On 9/10/19, 3:50 PM, "Linux-aspeed on behalf of Vijay Khemka" <linux-aspeed-bounces+vijaykhemka=fb.com@xxxxxxxxxxxxxxxx on behalf of vijaykhemka@xxxxxx> wrote:
On 9/10/19, 3:05 PM, "Florian Fainelli" <f.fainelli@xxxxxxxxx> 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?
I changed code from (netdev->hw_features &= ~NETIF_F_HW_CSUM) to
(netdev->hw_features &= ~NETIF_F_ IPV6_CSUM). And it is not working.
Don't know why. IPV4 works without any change but IPv6 needs HW_CSUM
Now I changed to
netdev->hw_features &= (~NETIF_F_HW_CSUM) | NETIF_F_IP_CSUM;
And it works.
I investigated more on these features and found that we cannot set NETIF_F_IP_CSUM
While NETIF_F_HW_CSUM is set. So I disabled NETIF_F_HW_CSUM first and enabled
NETIF_F_IP_CSUM in next statement. And it works fine.
But as per line 166 in include/linux/skbuff.h,
* NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
* NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
* checksum offload capability.
Please suggest which of below 2 I should do. As both works for me.
1. Disable completely NETIF_F_HW_CSUM and do nothing. This is original patch.
2. Enable NETIF_F_IP_CSUM in addition to 1. I can have v2 if this is accepted.
> Signed-off-by: Vijay Khemka <vijaykhemka@xxxxxx>
> 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")))
> 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);