mt76x02u: remove bogus check and comment padding

In mt76x02u_skb_dma_info() pad is always non-zero. Patch removes
bogus check and add comments to the function.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c
index 098d05e109e710dd076968b4523d8944b36be582..43f07461c8d39b6045388c8bbe59b1d2b0fcd6e8 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c
@@ -49,7 +49,12 @@ int mt76x02u_skb_dma_info(struct sk_buff *skb, int port, u32 flags)
               FIELD_PREP(MT_TXD_INFO_DPORT, port) | flags;
        put_unaligned_le32(info, skb_push(skb, sizeof(info)));
 
+       /* Add zero pad of 4 - 7 bytes */
        pad = round_up(skb->len, 4) + 4 - skb->len;
+
+       /* First packet of a A-MSDU burst keeps track of the whole burst
+        * length, need to update lenght of it and the last packet.
+        */
        skb_walk_frags(skb, iter) {
                last = iter;
                if (!iter->next) {
@@ -59,11 +64,10 @@ int mt76x02u_skb_dma_info(struct sk_buff *skb, int port, u32 flags)
                }
        }
 
-       if (unlikely(pad)) {
-               if (skb_pad(last, pad))
-                       return -ENOMEM;
-               __skb_put(last, pad);
-       }
+       if (skb_pad(last, pad))
+               return -ENOMEM;
+       __skb_put(last, pad);
+
        return 0;
 }