From 18b46810eb61f1d1a66c5511d12e84ea8cb7f35c Mon Sep 17 00:00:00 2001
From: Alexandre TORGUE <alexandre.torgue@st.com>
Date: Fri, 8 Apr 2016 11:18:03 +0200
Subject: [PATCH] net: ethernet: stmmac: GMAC4.xx: Fix TX descriptor
 preparation

On GMAC4.xx each descriptor contains 2 buffers of 16KB (each).
Initially, those 2 buffers was filled in dwmac4_rd_prepare_tx_desc but
it is actually not needed. Indeed, stmmac driver supports frame up to
9000 bytes (jumbo). So only one buffer is needed.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index d4952c7a836db..4ec7397e7fb37 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -254,14 +254,7 @@ static void dwmac4_rd_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 {
 	unsigned int tdes3 = p->des3;
 
-	if (unlikely(len > BUF_SIZE_16KiB)) {
-		p->des2 |= (((len - BUF_SIZE_16KiB) <<
-			     TDES2_BUFFER2_SIZE_MASK_SHIFT)
-			    & TDES2_BUFFER2_SIZE_MASK)
-			    | (BUF_SIZE_16KiB & TDES2_BUFFER1_SIZE_MASK);
-	} else {
-		p->des2 |= (len & TDES2_BUFFER1_SIZE_MASK);
-	}
+	p->des2 |= (len & TDES2_BUFFER1_SIZE_MASK);
 
 	if (is_fs)
 		tdes3 |= TDES3_FIRST_DESCRIPTOR;
-- 
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