Re: [PATCH] wifi: mt76: add tx checksum offload for mt7915, mt7921, mt7981 and mt7986

[Ben Greear <greearb@candelatech.com>]

On 10/19/25 08:51, Aleksander Jan Bajkowski wrote:
> Supports IPv4 and IPv6 TCP + UDP
> 
> In various tests between MT7986 and Intel BE200, I observed a performance
> boost ranging from 2 to 12%, with an average of 5.5%.
> 
> I did the tests on the MT7915, MT7981, MT7986, and MT7921 variants. The
> MT7922, MT7925, and MT799x are untouched for now and still have
> checksumming disabled.

At least with  7996, tcp csum only worked on the first few vdevs
created in our testing, so we had to add logic to disable that flag
on subsequent vdevs.

Have you tried creating a bunch of station and/or vap vdevs to see if
all of them can still transmit TCP traffic?

Thanks,
Ben


> 
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> [rebased and resolved conflicts]
> Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
> ---
>   drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c | 5 +++++
>   drivers/net/wireless/mediatek/mt76/mt7915/init.c     | 3 ++-
>   drivers/net/wireless/mediatek/mt76/mt792x_core.c     | 3 +++
>   3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
> index 0db00efe88b0..e31b3e7e2038 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
> @@ -372,6 +372,9 @@ mt76_connac2_mac_write_txwi_8023(__le32 *txwi, struct sk_buff *skb,
>   		wmm = sta->wme;
>   	}
>   
> +	val = FIELD_PREP(MT_TXD0_ETH_TYPE_OFFSET, 10);
> +	txwi[0] |= cpu_to_le32(val);
> +
>   	val = FIELD_PREP(MT_TXD1_HDR_FORMAT, MT_HDR_FORMAT_802_3) |
>   	      FIELD_PREP(MT_TXD1_TID, tid);
>   
> @@ -391,6 +394,8 @@ mt76_connac2_mac_write_txwi_8023(__le32 *txwi, struct sk_buff *skb,
>   
>   	val = FIELD_PREP(MT_TXD7_TYPE, fc_type) |
>   	      FIELD_PREP(MT_TXD7_SUB_TYPE, fc_stype);
> +	if (skb->ip_summed == CHECKSUM_PARTIAL)
> +		val |= MT_TXD7_IP_SUM | MT_TXD7_UDP_TCP_SUM;
>   
>   	txwi[7] |= cpu_to_le32(val);
>   }
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
> index 5ea8b46e092e..a3bab240afb7 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
> @@ -359,7 +359,8 @@ mt7915_init_wiphy(struct mt7915_phy *phy)
>   	hw->queues = 4;
>   	hw->max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF_HE;
>   	hw->max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF_HE;
> -	hw->netdev_features = NETIF_F_RXCSUM;
> +	hw->netdev_features = NETIF_F_RXCSUM |
> +			      NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
>   
>   	if (mtk_wed_device_active(&mdev->mmio.wed))
>   		hw->netdev_features |= NETIF_F_HW_TC;
> diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_core.c b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
> index c0e56541a954..fe138d2e8e62 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt792x_core.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
> @@ -632,6 +632,9 @@ int mt792x_init_wiphy(struct ieee80211_hw *hw)
>   	}
>   	hw->netdev_features = NETIF_F_RXCSUM;
>   
> +	if (is_mt7921(&dev->mt76))
> +		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
> +
>   	hw->radiotap_timestamp.units_pos =
>   		IEEE80211_RADIOTAP_TIMESTAMP_UNIT_US;
>   

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com