[PATCH net-next 3/6] net: mvneta: discriminate error cause for missed packet

[Gregory CLEMENT]

From: Yelena Krivosheev <yel...@marvell.com>

In order to improve the diagnostic in case of error, make the distinction
between refill error and skb allocation error.

Signed-off-by: Yelena Krivosheev <yel...@marvell.com>
[gregory: extract from a larger patch]
Signed-off-by: Gregory CLEMENT <gregory.clem...@bootlin.com>
---
 drivers/net/ethernet/marvell/mvneta.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c 
b/drivers/net/ethernet/marvell/mvneta.c
index 531227e2e48e..2c575c6732ce 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -589,9 +589,6 @@ struct mvneta_rx_queue {
        /* num of rx descriptors in the rx descriptor ring */
        int size;
 
-       /* counter of times when mvneta_refill() failed */
-       int missed;
-
        u32 pkts_coal;
        u32 time_coal;
 
@@ -609,6 +606,10 @@ struct mvneta_rx_queue {
 
        /* Index of the next RX DMA descriptor to process */
        int next_desc_to_proc;
+
+       /* error counters */
+       u32 skb_alloc_err;
+       u32 refill_err;
 };
 
 static enum cpuhp_state online_hpstate;
@@ -1946,8 +1947,13 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int 
rx_todo,
                if (rx_bytes <= rx_copybreak) {
                /* better copy a small frame and not unmap the DMA region */
                        skb = netdev_alloc_skb_ip_align(dev, rx_bytes);
-                       if (unlikely(!skb))
+                       if (unlikely(!skb)) {
+                               netdev_err(dev,
+                                          "Can't allocate skb on queue %d\n",
+                                          rxq->id);
+                               rxq->skb_alloc_err++;
                                goto err_drop_frame;
+                       }
 
                        dma_sync_single_range_for_cpu(dev->dev.parent,
                                                      phys_addr,
@@ -1972,7 +1978,7 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int 
rx_todo,
                err = mvneta_rx_refill(pp, rx_desc, rxq);
                if (err) {
                        netdev_err(dev, "Linux processing - Can't refill\n");
-                       rxq->missed++;
+                       rxq->refill_err++;
                        goto err_drop_frame;
                }
 
@@ -2102,7 +2108,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int 
rx_todo,
                err = hwbm_pool_refill(&bm_pool->hwbm_pool, GFP_ATOMIC);
                if (err) {
                        netdev_err(dev, "Linux processing - Can't refill\n");
-                       rxq->missed++;
+                       rxq->refill_err++;
                        goto err_drop_frame_ret_pool;
                }
 
-- 
2.17.1