[PATCH v2 1/3] wifi: mt76: Separate skb and ptr pointers in mt76_txwi_cache

[Eason Lai]

Split the skb/ptr union into separate skb and ptr fields to
support keeping both the SKB pointer and page pool pointer
at the same time.

Also add skip_unmap flag to tx_info.buf to handle cases where DMA
unmapping should be skipped.

Signed-off-by: Eason Lai <eason.lai at mediatek.com>
---
v2: revert to original naming for less intrusive
---
 drivers/net/wireless/mediatek/mt76/dma.c  | 15 +++++++++++----
 drivers/net/wireless/mediatek/mt76/mt76.h |  6 ++----
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 1658c37835cf..57632656eafa 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -43,6 +43,7 @@ mt76_alloc_rxwi(struct mt76_dev *dev)
 	if (!t)
 		return NULL;
 
+	t->skb = NULL;
 	t->ptr = NULL;
 	return t;
 }
@@ -84,8 +85,11 @@ mt76_get_txwi(struct mt76_dev *dev)
 {
 	struct mt76_txwi_cache *t = __mt76_get_txwi(dev);
 
-	if (t)
+	if (t) {
+		t->skb = NULL;
+		t->ptr = NULL;
 		return t;
+	}
 
 	return mt76_alloc_txwi(dev);
 }
@@ -716,6 +720,7 @@ mt76_dma_tx_queue_skb(struct mt76_phy *phy, struct mt76_queue *q,
 			goto unmap;
 
 		tx_info.buf[n].addr = addr;
+		tx_info.buf[n].skip_unmap = false;
 		tx_info.buf[n++].len = iter->len;
 	}
 	tx_info.nbuf = n;
@@ -740,9 +745,11 @@ mt76_dma_tx_queue_skb(struct mt76_phy *phy, struct mt76_queue *q,
 				tx_info.info, tx_info.skb, t);
 
 unmap:
-	for (n--; n > 0; n--)
-		dma_unmap_single(dev->dma_dev, tx_info.buf[n].addr,
-				 tx_info.buf[n].len, DMA_TO_DEVICE);
+	for (n--; n > 0; n--) {
+		if (!tx_info.buf[n].skip_unmap)
+			dma_unmap_single(dev->dma_dev, tx_info.buf[n].addr,
+					 tx_info.buf[n].len, DMA_TO_DEVICE);
+	}
 
 free:
 #ifdef CONFIG_NL80211_TESTMODE
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 0090e16e8f78..ec679d12a2af 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -446,10 +446,8 @@ struct mt76_txwi_cache {
 	struct list_head list;
 	dma_addr_t dma_addr;
 
-	union {
-		struct sk_buff *skb;
-		void *ptr;
-	};
+	struct sk_buff *skb;
+	void *ptr;
 
 	u8 qid;
 	u8 phy_idx;
-- 
2.45.2