diff --git a/target/linux/bcm53xx/patches-5.10/700-bgmac-reduce-max-frame-size-to-support-just-MTU-1500.patch b/target/linux/bcm53xx/patches-5.10/700-bgmac-reduce-max-frame-size-to-support-just-MTU-1500.patch new file mode 100644 index 00000000000..2c2eb07b82d --- /dev/null +++ b/target/linux/bcm53xx/patches-5.10/700-bgmac-reduce-max-frame-size-to-support-just-MTU-1500.patch @@ -0,0 +1,33 @@ +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= +Date: Fri, 10 Jun 2022 13:10:47 +0200 +Subject: [PATCH] bgmac: reduce max frame size to support just MTU 1500 +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +bgmac allocates new replacement buffer before handling each received +frame. Allocating & DMA-preparing 9724 B each time consumes a lot of CPU +time. Ideally bgmac should just respect currently set MTU but it isn't +the case right now. For now just revert back to the old limited frame +size. + +This change bumps NAT masquarade speed by ~95%. + +Ref: 8c7da63978f1 ("bgmac: configure MTU and add support for frames beyond 8192 byte size") +Signed-off-by: Rafał Miłecki +--- + drivers/net/ethernet/broadcom/bgmac.h | 3 +-- + 1 file changed, 1 insertion(+), 2 deletions(-) + +--- a/drivers/net/ethernet/broadcom/bgmac.h ++++ b/drivers/net/ethernet/broadcom/bgmac.h +@@ -366,8 +366,7 @@ + #define BGMAC_RX_FRAME_OFFSET 30 /* There are 2 unused bytes between header and real data */ + #define BGMAC_RX_BUF_OFFSET (NET_SKB_PAD + NET_IP_ALIGN - \ + BGMAC_RX_FRAME_OFFSET) +-/* Jumbo frame size with FCS */ +-#define BGMAC_RX_MAX_FRAME_SIZE 9724 ++#define BGMAC_RX_MAX_FRAME_SIZE 1536 + #define BGMAC_RX_BUF_SIZE (BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE) + #define BGMAC_RX_ALLOC_SIZE (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))