Re: [PATCH net-next 5/8] net: ethernet: mtk_eth_soc: add MTK_NETSYS_V3 capability bit

From: Russell King (Oracle)
Date: Mon Jun 12 2023 - 07:38:17 EST


On Sun, Jun 11, 2023 at 01:38:23AM +0100, Daniel Golle wrote:
> @@ -1333,8 +1354,13 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
> mtk_tx_set_dma_desc(dev, itxd, &txd_info);
>
> itx_buf->flags |= MTK_TX_FLAGS_SINGLE0;
> - itx_buf->flags |= (!mac->id) ? MTK_TX_FLAGS_FPORT0 :
> - MTK_TX_FLAGS_FPORT1;
> + if (mac->id == MTK_GMAC1_ID)
> + itx_buf->flags |= MTK_TX_FLAGS_FPORT0;
> + else if (mac->id == MTK_GMAC2_ID)
> + itx_buf->flags |= MTK_TX_FLAGS_FPORT1;
> + else
> + itx_buf->flags |= MTK_TX_FLAGS_FPORT2;

There appears to be two places that this code structure appears, and
this is in the path for packet transmission. I wonder if it would be
more efficient to instead do:

itx_buf->flags |= MTK_TX_FLAGS_SINGLE0 | mac->tx_flags;

with mac->tx_flags appropriately initialised?

> @@ -2170,7 +2214,9 @@ static int mtk_poll_tx_qdma(struct mtk_eth *eth, int budget,
> tx_buf = mtk_desc_to_tx_buf(ring, desc,
> eth->soc->txrx.txd_size);
> if (tx_buf->flags & MTK_TX_FLAGS_FPORT1)
> - mac = 1;
> + mac = MTK_GMAC2_ID;
> + else if (tx_buf->flags & MTK_TX_FLAGS_FPORT2)
> + mac = MTK_GMAC3_ID;

This has me wondering whether the flags are used for hardware or just
for the driver's purposes. If it's the latter, can we instead store the
MAC index in tx_buf, rather than having to decode a bitfield?

I suspect these are just for the driver given that the addition of
MTK_TX_FLAGS_FPORT2 changes all subsequent bit numbers in this struct
member.

>
> if (!tx_buf->data)
> break;
> @@ -3783,7 +3829,26 @@ static int mtk_hw_init(struct mtk_eth *eth, bool reset)
> mtk_w32(eth, eth->soc->txrx.rx_irq_done_mask, reg_map->qdma.int_grp + 4);
> mtk_w32(eth, 0x21021000, MTK_FE_INT_GRP);
>
> - if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V3)) {
> + /* PSE should not drop port1, port8 and port9 packets */
> + mtk_w32(eth, 0x00000302, PSE_DROP_CFG);
> +
> + /* GDM and CDM Threshold */
> + mtk_w32(eth, 0x00000707, MTK_CDMW0_THRES);
> + mtk_w32(eth, 0x00000077, MTK_CDMW1_THRES);
> +
> + /* Disable GDM1 RX CRC stripping */
> + val = mtk_r32(eth, MTK_GDMA_FWD_CFG(0));
> + val &= ~MTK_GDMA_STRP_CRC;
> + mtk_w32(eth, val, MTK_GDMA_FWD_CFG(0));

mtk_m32() ?

Thanks!

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