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
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
commit 01ffc0a7f1c1801a2354719dedbc32aff45b987d
Author: David Woodhouse <dwmw2@infradead.org>
Date: Sat Nov 24 12:11:21 2012 +0000
8139cp: re-enable interrupts after tx timeout
Recovery doesn't work too well if we leave interrupts disabled...
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 871f0d4c153e1258d4becf306eca6761bf38b629
Author: David Woodhouse <dwmw2@infradead.org>
Date: Thu Nov 22 03:16:58 2012 +0000
8139cp: enable bql
This adds support for byte queue limits on RTL8139C+
Tested on real hardware.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-By: Dave Täht <dave.taht@bufferbloat.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit a9dbe40fc10cea2efe6e1ff9e03c62dd7579c5ba
Author: David Woodhouse <dwmw2@infradead.org>
Date: Wed Nov 21 10:27:19 2012 +0000
8139cp: set ring address after enabling C+ mode
This fixes (for me) a regression introduced by commit b01af457 ("8139cp:
set ring address before enabling receiver"). That commit configured the
descriptor ring addresses earlier in the initialisation sequence, in
order to avoid the possibility of triggering stray DMA before the
correct address had been set up.
Unfortunately, it seems that the hardware will scribble garbage into the
TxRingAddr registers when we enable "plus mode" Tx in the CpCmd
register. Observed on a Traverse Geos router board.
To deal with this, while not reintroducing the problem which led to the
original commit, we augment cp_start_hw() to write to the CpCmd register
*first*, then set the descriptor ring addresses, and then finally to
enable Rx and Tx in the original 8139 Cmd register. The datasheet
actually indicates that we should enable Tx/Rx in the Cmd register
*before* configuring the descriptor addresses, but that would appear to
re-introduce the problem that the offending commit b01af457 was trying
to solve. And this variant appears to work fine on real hardware.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.5+]
Signed-off-by: David S. Miller <davem@davemloft.net>
--- a/drivers/net/ethernet/realtek/8139cp.c
+++ b/drivers/net/ethernet/realtek/8139cp.c
@@ -648,6 +648,7 @@ static void cp_tx (struct cp_private *cp
{
unsigned tx_head = cp->tx_head;
unsigned tx_tail = cp->tx_tail;
+ unsigned bytes_compl = 0, pkts_compl = 0;
while (tx_tail != tx_head) {
struct cp_desc *txd = cp->tx_ring + tx_tail;
@@ -666,6 +667,9 @@ static void cp_tx (struct cp_private *cp
le32_to_cpu(txd->opts1) & 0xffff,
PCI_DMA_TODEVICE);
+ bytes_compl += skb->len;
+ pkts_compl++;
+
if (status & LastFrag) {
if (status & (TxError | TxFIFOUnder)) {
netif_dbg(cp, tx_err, cp->dev,
@@ -697,6 +701,7 @@ static void cp_tx (struct cp_private *cp
cp->tx_tail = tx_tail;
+ netdev_completed_queue(cp->dev, pkts_compl, bytes_compl);
if (TX_BUFFS_AVAIL(cp) > (MAX_SKB_FRAGS + 1))
netif_wake_queue(cp->dev);
}
@@ -843,6 +848,8 @@ static netdev_tx_t cp_start_xmit (struct
wmb();
}
cp->tx_head = entry;
+
+ netdev_sent_queue(dev, skb->len);
netif_dbg(cp, tx_queued, cp->dev, "tx queued, slot %d, skblen %d\n",
entry, skb->len);
if (TX_BUFFS_AVAIL(cp) <= (MAX_SKB_FRAGS + 1))
@@ -937,6 +944,8 @@ static void cp_stop_hw (struct cp_privat
cp->rx_tail = 0;
cp->tx_head = cp->tx_tail = 0;
+
+ netdev_reset_queue(cp->dev);
}
static void cp_reset_hw (struct cp_private *cp)
@@ -957,8 +966,38 @@ static void cp_reset_hw (struct cp_priva
static inline void cp_start_hw (struct cp_private *cp)
{
+ dma_addr_t ring_dma;
+
cpw16(CpCmd, cp->cpcmd);
+
+ /*
+ * These (at least TxRingAddr) need to be configured after the
+ * corresponding bits in CpCmd are enabled. Datasheet v1.6 §6.33
+ * (C+ Command Register) recommends that these and more be configured
+ * *after* the [RT]xEnable bits in CpCmd are set. And on some hardware
+ * it's been observed that the TxRingAddr is actually reset to garbage
+ * when C+ mode Tx is enabled in CpCmd.
+ */
+ cpw32_f(HiTxRingAddr, 0);
+ cpw32_f(HiTxRingAddr + 4, 0);
+
+ ring_dma = cp->ring_dma;
+ cpw32_f(RxRingAddr, ring_dma & 0xffffffff);
+ cpw32_f(RxRingAddr + 4, (ring_dma >> 16) >> 16);
+
+ ring_dma += sizeof(struct cp_desc) * CP_RX_RING_SIZE;
+ cpw32_f(TxRingAddr, ring_dma & 0xffffffff);
+ cpw32_f(TxRingAddr + 4, (ring_dma >> 16) >> 16);
+
+ /*
+ * Strictly speaking, the datasheet says this should be enabled
+ * *before* setting the descriptor addresses. But what, then, would
+ * prevent it from doing DMA to random unconfigured addresses?
+ * This variant appears to work fine.
+ */
cpw8(Cmd, RxOn | TxOn);
+
+ netdev_reset_queue(cp->dev);
}
static void cp_enable_irq(struct cp_private *cp)
@@ -969,7 +1008,6 @@ static void cp_enable_irq(struct cp_priv
static void cp_init_hw (struct cp_private *cp)
{
struct net_device *dev = cp->dev;
- dma_addr_t ring_dma;
cp_reset_hw(cp);
@@ -979,17 +1017,6 @@ static void cp_init_hw (struct cp_privat
cpw32_f (MAC0 + 0, le32_to_cpu (*(__le32 *) (dev->dev_addr + 0)));
cpw32_f (MAC0 + 4, le32_to_cpu (*(__le32 *) (dev->dev_addr + 4)));
- cpw32_f(HiTxRingAddr, 0);
- cpw32_f(HiTxRingAddr + 4, 0);
-
- ring_dma = cp->ring_dma;
- cpw32_f(RxRingAddr, ring_dma & 0xffffffff);
- cpw32_f(RxRingAddr + 4, (ring_dma >> 16) >> 16);
-
- ring_dma += sizeof(struct cp_desc) * CP_RX_RING_SIZE;
- cpw32_f(TxRingAddr, ring_dma & 0xffffffff);
- cpw32_f(TxRingAddr + 4, (ring_dma >> 16) >> 16);
-
cp_start_hw(cp);
cpw8(TxThresh, 0x06); /* XXX convert magic num to a constant */
@@ -1192,6 +1219,7 @@ static void cp_tx_timeout(struct net_dev
cp_clean_rings(cp);
rc = cp_init_rings(cp);
cp_start_hw(cp);
+ cp_enable_irq(cp);
netif_wake_queue(dev);
|
