[PATCH mt76-next 14/29] wifi: mt76: only consume the WO drop bit on WED v2 devices

[Felix Fietkau <nbd@nbd.name>]

The RX path is handled by the WO MCU only on WED v2 hardware. On WED
v3 the same buf1 bit does not carry drop information, so evaluating it
there causes spurious RX drops.

Fixes: e4d2b8bcac11 ("wifi: mt76: drop the incorrect scatter and gather frame")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 drivers/net/wireless/mediatek/mt76/dma.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 1658c37835cf..a67880a9281c 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -547,8 +547,13 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
 		t->ptr = NULL;
 
 		mt76_put_rxwi(dev, t);
-		if (drop)
+#ifdef CONFIG_NET_MEDIATEK_SOC_WED
+		/* the WO MCU owns the RX path only on WED v2, on newer
+		 * versions this buf1 bit carries no drop information
+		 */
+		if (drop && dev->mmio.wed.version == 2)
 			*drop |= !!(buf1 & MT_DMA_CTL_WO_DROP);
+#endif
 	} else {
 		dma_sync_single_for_cpu(dev->dma_dev, e->dma_addr[0],
 				SKB_WITH_OVERHEAD(q->buf_size),
-- 
2.53.0