> From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
>
> This is a tricky beast to understand, so add some notes for
> next time someone is looking at this code and trying to compare
> against documents.
>
> Signed-off-by: Ben Greear <greearb@xxxxxxxxxxxxxxx>
> ---
>
> txs and related patches rebased on top of 5.16
>
> .../net/wireless/mediatek/mt76/mt7915/mac.c | 23 +++++++++++++++----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
> index 8e5b87af2efb..6fbd58ae9c88 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
> @@ -410,6 +410,7 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
> __le32 *rxd = (__le32 *)skb->data;
> __le32 *rxv = NULL;
> u32 mode = 0;
> + /* table "PP -> HOST / X-CPU" RX Format */
> u32 rxd0 = le32_to_cpu(rxd[0]);
> u32 rxd1 = le32_to_cpu(rxd[1]);
> u32 rxd2 = le32_to_cpu(rxd[2]);
> @@ -489,7 +490,7 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
>
> rxd += 6;
> if (rxd1 & MT_RXD1_NORMAL_GROUP_4) {
> - u32 v0 = le32_to_cpu(rxd[0]);
> + u32 v0 = le32_to_cpu(rxd[0]); /* DW6 */
> u32 v2 = le32_to_cpu(rxd[2]);
>
> fc = cpu_to_le16(FIELD_GET(MT_RXD6_FRAME_CONTROL, v0));
> @@ -502,6 +503,7 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
> }
>
> if (rxd1 & MT_RXD1_NORMAL_GROUP_1) {
> + /* DW10, assuming Group-4 enabled */
> u8 *data = (u8 *)rxd;
>
> if (status->flag & RX_FLAG_DECRYPTED) {
> @@ -533,6 +535,7 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
> }
>
> if (rxd1 & MT_RXD1_NORMAL_GROUP_2) {
> + /* DW14, assuming group-1,4 */
> status->timestamp = le32_to_cpu(rxd[0]);
> status->flag |= RX_FLAG_MACTIME_START;
>
> @@ -558,18 +561,22 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
> if (rxd1 & MT_RXD1_NORMAL_GROUP_3) {
> u32 v0, v1, v2;
>
> - rxv = rxd;
> + rxv = rxd; /* DW16 assuming group 1,2,3,4 */
> rxd += 2;
> if ((u8 *)rxd - skb->data >= skb->len)
> return -EINVAL;
>
> - v0 = le32_to_cpu(rxv[0]);
> + v0 = le32_to_cpu(rxv[0]); /* DW16, P-VEC1 31:0 */
> + /* DW17, RX_RCPI copied over P-VEC 64:32 Per RX Format doc. */
This seems not so useful for everybody.
> v1 = le32_to_cpu(rxv[1]);
> - v2 = le32_to_cpu(rxv[2]);
> + v2 = le32_to_cpu(rxv[2]); /* first DW of group-5, C-RXV */
>
> if (v0 & MT_PRXV_HT_AD_CODE)
> status->enc_flags |= RX_ENC_FLAG_LDPC;
>
> + /* TODO: When group-5 is enabled, use nss (and stbc) to
> + * calculate chains properly for this particular skb.
> + */
> status->chains = mphy->antenna_mask;
> status->chain_signal[0] = to_rssi(MT_PRXV_RCPI0, v1);
> status->chain_signal[1] = to_rssi(MT_PRXV_RCPI1, v1);
> @@ -581,12 +588,18 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
> if (!(status->chains & BIT(i)))
> continue;
>
> + /* TODO: Use db sum logic instead of max. */
This seems just a not for you :)
> status->signal = max(status->signal,
> status->chain_signal[i]);
> }
>
> - /* RXD Group 5 - C-RXV */
> + /* RXD Group 5 - C-RXV.
> + * Group 5 Not currently enabled for 7915 except in
> + * monitor mode.
> + * See MT_DMA_DCR0_RXD_G5_EN
> + */
> if (rxd1 & MT_RXD1_NORMAL_GROUP_5) {
> + /* See RXV document ... */
This is not so useful :)
> u8 stbc = FIELD_GET(MT_CRXV_HT_STBC, v2);
> u8 gi = FIELD_GET(MT_CRXV_HT_SHORT_GI, v2);
> bool cck = false;
> --
> 2.20.1
>
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