1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 22:23:07 +0200
Subject: [PATCH] bgmac: simplify rx DMA error handling
Unmap the DMA buffer before checking it. If an error occurs, free the
buffer and allocate a new one. If allocation or mapping fails, retry as
long as there is NAPI poll budget left (count every attempt instead of
every frame).
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -404,51 +404,33 @@ static int bgmac_dma_rx_read(struct bgma
void *buf = slot->buf;
u16 len, flags;
- /* Unmap buffer to make it accessible to the CPU */
- dma_sync_single_for_cpu(dma_dev, slot->dma_addr,
- BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
-
- /* Get info from the header */
- len = le16_to_cpu(rx->len);
- flags = le16_to_cpu(rx->flags);
+ if (++handled >= weight - 1) /* Should never be greater */
+ break;
do {
- dma_addr_t old_dma_addr = slot->dma_addr;
- int err;
+ if (!slot->dma_addr)
+ break;
+
+ /* Unmap buffer to make it accessible to the CPU */
+ dma_unmap_single(dma_dev, slot->dma_addr,
+ BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
+ slot->dma_addr = 0;
+
+ /* Get info from the header */
+ len = le16_to_cpu(rx->len);
+ flags = le16_to_cpu(rx->flags);
/* Check for poison and drop or pass the packet */
if (len == 0xdead && flags == 0xbeef) {
bgmac_err(bgmac, "Found poisoned packet at slot %d, DMA issue!\n",
ring->start);
- dma_sync_single_for_device(dma_dev,
- slot->dma_addr,
- BGMAC_RX_BUF_SIZE,
- DMA_FROM_DEVICE);
+ kfree(buf);
break;
}
/* Omit CRC. */
len -= ETH_FCS_LEN;
- /* Prepare new skb as replacement */
- err = bgmac_dma_rx_skb_for_slot(bgmac, slot);
- if (err) {
- /* Poison the old skb */
- rx->len = cpu_to_le16(0xdead);
- rx->flags = cpu_to_le16(0xbeef);
-
- dma_sync_single_for_device(dma_dev,
- slot->dma_addr,
- BGMAC_RX_BUF_SIZE,
- DMA_FROM_DEVICE);
- break;
- }
- bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
-
- /* Unmap old skb, we'll pass it to the netfif */
- dma_unmap_single(dma_dev, old_dma_addr,
- BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
-
skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
skb_put(skb, BGMAC_RX_FRAME_OFFSET +
BGMAC_RX_BUF_OFFSET + len);
@@ -458,14 +440,16 @@ static int bgmac_dma_rx_read(struct bgma
skb_checksum_none_assert(skb);
skb->protocol = eth_type_trans(skb, bgmac->net_dev);
napi_gro_receive(&bgmac->napi, skb);
- handled++;
} while (0);
+ /* Prepare new skb as replacement */
+ if (bgmac_dma_rx_skb_for_slot(bgmac, slot))
+ continue;
+
+ bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
+
if (++ring->start >= BGMAC_RX_RING_SLOTS)
ring->start = 0;
-
- if (handled >= weight) /* Should never be greater */
- break;
}
return handled;
|
