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From:   Aaro Koskinen <aaro.koskinen@iki.fi>
To:     "David S. Miller" <davem@davemloft.net>,
        Jose Abreu <joabreu@synopsys.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        netdev@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Aaro Koskinen <aaro.koskinen@nokia.com>
Subject: [PATCH 4/6] net: stmmac: don't overwrite discard_frame status
Date:   Wed, 27 Mar 2019 22:35:38 +0200
Message-Id: <20190327203540.1884-5-aaro.koskinen@iki.fi>
In-Reply-To: <20190327203540.1884-1-aaro.koskinen@iki.fi>
References: <20190327203540.1884-1-aaro.koskinen@iki.fi>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Aaro Koskinen <aaro.koskinen@nokia.com>

If we have error bits set, the discard_frame status will get overwritten
by checksum bit checks, which might set the status back to good one.
Fix by checking the COE status only if the frame is good.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
---
 drivers/net/ethernet/stmicro/stmmac/enh_desc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
index e8855e6adb48..c42ef6c729c0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
@@ -231,9 +231,10 @@ static int enh_desc_get_rx_status(void *data, struct stmmac_extra_stats *x,
 	 * It doesn't match with the information reported into the databook.
 	 * At any rate, we need to understand if the CSUM hw computation is ok
 	 * and report this info to the upper layers. */
-	ret = enh_desc_coe_rdes0(!!(rdes0 & RDES0_IPC_CSUM_ERROR),
-				 !!(rdes0 & RDES0_FRAME_TYPE),
-				 !!(rdes0 & ERDES0_RX_MAC_ADDR));
+	if (likely(ret == good_frame))
+		ret = enh_desc_coe_rdes0(!!(rdes0 & RDES0_IPC_CSUM_ERROR),
+					 !!(rdes0 & RDES0_FRAME_TYPE),
+					 !!(rdes0 & ERDES0_RX_MAC_ADDR));
 
 	if (unlikely(rdes0 & RDES0_DRIBBLING))
 		x->dribbling_bit++;
-- 
2.17.0