target/linux/bcm47xx/patches-5.15/701-net-bgmac-connect-to-PHY-even-if-it-is-BGMAC_PHY_NOR.patch

   1 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   2 Date: Fri, 10 Jun 2022 13:10:47 +0200
   3 Subject: [PATCH] bgmac: reduce max frame size to support just MTU 1500
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   7
   8 bgmac allocates new replacement buffer before handling each received
   9 frame. Allocating & DMA-preparing 9724 B each time consumes a lot of CPU
  10 time. Ideally bgmac should just respect currently set MTU but it isn't
  11 the case right now. For now just revert back to the old limited frame
  12 size.
  13
  14 This change bumps NAT masquarade speed by ~95%.
  15
  16 Ref: 8c7da63978f1 ("bgmac: configure MTU and add support for frames beyond 8192 byte size")
  17 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  18 ---
  19  drivers/net/ethernet/broadcom/bgmac.h | 3 +--
  20  1 file changed, 1 insertion(+), 2 deletions(-)
  21
  22 --- a/drivers/net/ethernet/broadcom/bgmac.h
  23 +++ b/drivers/net/ethernet/broadcom/bgmac.h
  24 @@ -328,8 +328,7 @@
  25  #define BGMAC_RX_FRAME_OFFSET                  30              /* There are 2 unused bytes between header and real data */
  26  #define BGMAC_RX_BUF_OFFSET                    (NET_SKB_PAD + NET_IP_ALIGN - \
  27                                                  BGMAC_RX_FRAME_OFFSET)
  28 -/* Jumbo frame size with FCS */
  29 -#define BGMAC_RX_MAX_FRAME_SIZE                        9724
  30 +#define BGMAC_RX_MAX_FRAME_SIZE                        1536
  31  #define BGMAC_RX_BUF_SIZE                      (BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE)
  32  #define BGMAC_RX_ALLOC_SIZE                    (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \
  33                                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))