target/linux/generic/backport-5.15/730-10-v6.3-net-ethernet-mtk_eth_soc-drop-packets-to-WDMA-if-the.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Thu, 3 Nov 2022 17:46:25 +0100
   3 Subject: [PATCH] net: ethernet: mtk_eth_soc: drop packets to WDMA if the
   4  ring is full
   5
   6 Improves handling of DMA ring overflow.
   7 Clarify other WDMA drop related comment.
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  13 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  14 @@ -3715,9 +3715,12 @@ static int mtk_hw_init(struct mtk_eth *e
  15         mtk_w32(eth, 0x21021000, MTK_FE_INT_GRP);
  16
  17         if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
  18 -               /* PSE should not drop port8 and port9 packets */
  19 +               /* PSE should not drop port8 and port9 packets from WDMA Tx */
  20                 mtk_w32(eth, 0x00000300, PSE_DROP_CFG);
  21
  22 +               /* PSE should drop packets to port 8/9 on WDMA Rx ring full */
  23 +               mtk_w32(eth, 0x00000300, PSE_PPE0_DROP);
  24 +
  25                 /* PSE Free Queue Flow Control  */
  26                 mtk_w32(eth, 0x01fa01f4, PSE_FQFC_CFG2);
  27
  28 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
  29 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
  30 @@ -140,6 +140,7 @@
  31  #define PSE_FQFC_CFG1          0x100
  32  #define PSE_FQFC_CFG2          0x104
  33  #define PSE_DROP_CFG           0x108
  34 +#define PSE_PPE0_DROP          0x110
  35
  36  /* PSE Input Queue Reservation Register*/
  37  #define PSE_IQ_REV(x)          (0x140 + (((x) - 1) << 2))