netdev - Re: [PATCH net-next 1/5] sky2: force receive checksum when using RSS on some hardware (v2)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 8 Jul 2011 10:45:33 +0200
From:	Michał Mirosław <mirqus@...il.com>
To:	Stephen Hemminger <shemminger@...tta.com>
Cc:	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: [PATCH net-next 1/5] sky2: force receive checksum when using RSS
 on some hardware (v2)

2011/7/8 Stephen Hemminger <shemminger@...tta.com>:
> Found when reviewing the vendor driver. Apparently some chip versions
> require receive checksumming to be enabled in order for RSS to work.
>
> Also, if fix_features has to change some settings; put in message
> in log in similar manner to netdev_fix_features.
>
> Signed-off-by: Stephen Hemminger <shemminger@...tta.com>
>
> ---
> v2 - enforce the requirement in fix_features rather than set features
>
> --- a/drivers/net/sky2.c        2011-07-07 13:56:03.575420273 -0700
> +++ b/drivers/net/sky2.c        2011-07-07 14:03:17.775403938 -0700
[...]
> @@ -4176,8 +4180,18 @@ static u32 sky2_fix_features(struct net_
>        /* In order to do Jumbo packets on these chips, need to turn off the
>         * transmit store/forward. Therefore checksum offload won't work.
>         */
> -       if (dev->mtu > ETH_DATA_LEN && hw->chip_id == CHIP_ID_YUKON_EC_U)
> +       if (dev->mtu > ETH_DATA_LEN && hw->chip_id == CHIP_ID_YUKON_EC_U) {
> +               netdev_warn(dev, "checksum offload not possible with jumbo frames\n");
>                features &= ~(NETIF_F_TSO|NETIF_F_SG|NETIF_F_ALL_CSUM);
> +       }
> +
> +       /* Some hardware requires receive checksum for RSS to work. */
> +       if ( (features & NETIF_F_RXHASH) &&
> +            !(features & NETIF_F_RXCSUM) &&
> +            (sky2->hw->flags & SKY2_HW_RSS_CHKSUM)) {
> +               netdev_warn(dev, "receive hashing forces receive checksum\n");
> +               features |= NETIF_F_RXCSUM;
> +       }
>
>        return features;
>  }

I suggest using netdev_dbg() instead of netdev_warn() so it won't spam
dmesg on every features update.

Otherwise, looks good.

Best Regards,
Michał Mirosław
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html