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From:   Alex Elder <elder@linaro.org>
To:     davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com
Cc:     lkp@intel.com, mka@chromium.org, evgreen@chromium.org,
        bjorn.andersson@linaro.org, quic_cpratapa@quicinc.com,
        quic_avuyyuru@quicinc.com, quic_jponduru@quicinc.com,
        quic_subashab@quicinc.com, elder@kernel.org,
        netdev@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net 1/3] net: ipa: certain dropped packets aren't accounted for
Date:   Thu, 12 May 2022 10:10:31 -0500
Message-Id: <20220512151033.211592-2-elder@linaro.org>
In-Reply-To: <20220512151033.211592-1-elder@linaro.org>
References: <20220512151033.211592-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

If an RX endpoint receives packets containing status headers, and a
packet in the buffer is not dropped, ipa_endpoint_skb_copy() is
responsible for wrapping the packet data in an SKB and forwarding it
to ipa_modem_skb_rx() for further processing.

If ipa_endpoint_skb_copy() gets a null pointer from build_skb(), it
just returns early.  But in the process it doesn't record that as a
dropped packet in the network device statistics.

Instead, call ipa_modem_skb_rx() whether or not the SKB pointer is
NULL; that function ensures the statistics are properly updated.

Fixes: 1b65bbcc9a710 ("net: ipa: skip SKB copy if no netdev")
Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 888e94278a84f..cea7b2e2ce969 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -1150,13 +1150,12 @@ static void ipa_endpoint_skb_copy(struct ipa_endpoint *endpoint,
 		return;
 
 	skb = __dev_alloc_skb(len, GFP_ATOMIC);
-	if (!skb)
-		return;
-
-	/* Copy the data into the socket buffer and receive it */
-	skb_put(skb, len);
-	memcpy(skb->data, data, len);
-	skb->truesize += extra;
+	if (skb) {
+		/* Copy the data into the socket buffer and receive it */
+		skb_put(skb, len);
+		memcpy(skb->data, data, len);
+		skb->truesize += extra;
+	}
 
 	ipa_modem_skb_rx(endpoint->netdev, skb);
 }
-- 
2.32.0