The following set of four patches provide some more spidernet fixes.
Most important are a pair of patches to stop the transmit queue when it
is full, and to actually turn off transmit interrupts during NAPI(!)
Signed-off-by: Linas Vepstas <[email protected]>
Cc: James K Lewis <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Subject: [PATCH 1/4]: Spidernet stop queue when queue is full.
This patch adds a call to netif_stop_queue() when there is
no more room for more packets on the transmit queue.
Signed-off-by: Linas Vepstas <[email protected]>
Cc: James K Lewis <[email protected]>
Cc: Arnd Bergmann <[email protected]>
----
drivers/net/spider_net.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
Index: linux-2.6.18-mm2/drivers/net/spider_net.c
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.c 2006-10-02 12:12:56.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.c 2006-10-02 18:59:43.000000000 -0500
@@ -686,6 +686,7 @@ spider_net_prepare_tx_descr(struct spide
/* Chain the bus address, so that the DMA engine finds this descr. */
descr->prev->next_descr_addr = descr->bus_addr;
+ card->netdev->trans_start = jiffies;
return 0;
}
@@ -857,29 +858,23 @@ spider_net_xmit(struct sk_buff *skb, str
spider_net_release_tx_chain(card, 0);
- if (chain->head->next == chain->tail->prev) {
- card->netdev_stats.tx_dropped++;
- result = NETDEV_TX_LOCKED;
- goto out;
- }
-
- if (spider_net_get_descr_status(descr) != SPIDER_NET_DESCR_NOT_IN_USE) {
- card->netdev_stats.tx_dropped++;
+ if ((chain->head->next == chain->tail->prev) ||
+ (spider_net_get_descr_status(descr) != SPIDER_NET_DESCR_NOT_IN_USE)) {
result = NETDEV_TX_LOCKED;
goto out;
}
if (spider_net_prepare_tx_descr(card, skb) != 0) {
- card->netdev_stats.tx_dropped++;
result = NETDEV_TX_BUSY;
goto out;
}
- result = NETDEV_TX_OK;
spider_net_kick_tx_dma(card);
+ return NETDEV_TX_OK;
out:
- netif_wake_queue(netdev);
+ card->netdev_stats.tx_dropped++;
+ netif_stop_queue(netdev);
return result;
}
@@ -898,6 +893,8 @@ spider_net_cleanup_tx_ring(struct spider
if ((spider_net_release_tx_chain(card, 0) != 0) &&
(card->netdev->flags & IFF_UP))
spider_net_kick_tx_dma(card);
+
+ netif_wake_queue(card->netdev);
}
/**
This patch fixes the names of a few fields in the DMA control
register. There is no functional change.
Signed-off-by: Linas Vepstas <[email protected]>
Cc: James K Lewis <[email protected]>
Cc: Arnd Bergmann <[email protected]>
----
drivers/net/spider_net.c | 2 +-
drivers/net/spider_net.h | 14 +++++++++-----
2 files changed, 10 insertions(+), 6 deletions(-)
Index: linux-2.6.18-mm2/drivers/net/spider_net.c
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.c 2006-10-02 18:59:43.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.c 2006-10-02 19:06:55.000000000 -0500
@@ -1639,7 +1639,7 @@ spider_net_enable_card(struct spider_net
SPIDER_NET_INT2_MASK_VALUE);
spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
- SPIDER_NET_GDTDCEIDIS);
+ SPIDER_NET_GDTBSTA);
}
/**
Index: linux-2.6.18-mm2/drivers/net/spider_net.h
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.h 2006-10-02 18:58:11.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.h 2006-10-02 19:06:55.000000000 -0500
@@ -191,7 +191,9 @@ extern char spider_net_driver_name[];
#define SPIDER_NET_MACMODE_VALUE 0x00000001
#define SPIDER_NET_BURSTLMT_VALUE 0x00000200 /* about 16 us */
-/* 1(0) enable r/tx dma
+/* DMAC control register GDMACCNTR
+ *
+ * 1(0) enable r/tx dma
* 0000000 fixed to 0
*
* 000000 fixed to 0
@@ -200,6 +202,7 @@ extern char spider_net_driver_name[];
*
* 000000 fixed to 0
* 00 burst alignment: 128 bytes
+ * 11 burst alignment: 1024 bytes
*
* 00000 fixed to 0
* 0 descr writeback size 32 bytes
@@ -210,10 +213,11 @@ extern char spider_net_driver_name[];
#define SPIDER_NET_DMA_RX_VALUE 0x80000000
#define SPIDER_NET_DMA_RX_FEND_VALUE 0x00030003
/* to set TX_DMA_EN */
-#define SPIDER_NET_TX_DMA_EN 0x80000000
-#define SPIDER_NET_GDTDCEIDIS 0x00000300
-#define SPIDER_NET_DMA_TX_VALUE SPIDER_NET_TX_DMA_EN | \
- SPIDER_NET_GDTDCEIDIS
+#define SPIDER_NET_TX_DMA_EN 0x80000000
+#define SPIDER_NET_GDTBSTA 0x00000300
+#define SPIDER_NET_GDTDCEIDIS 0x00000002
+#define SPIDER_NET_DMA_TX_VALUE SPIDER_NET_TX_DMA_EN | \
+ SPIDER_NET_GDTBSTA
#define SPIDER_NET_DMA_TX_FEND_VALUE 0x00030003
/* SPIDER_NET_UA_DESCR_VALUE is OR'ed with the unicast address */
For small packets, the transmit interrupt settings were
accidentally generating too many interrupts. This patch
turns off all transmit-related interrupts when the tx
queue is mostly empty.
Signed-off-by: Linas Vepstas <[email protected]>
Cc: James K Lewis <[email protected]>
Cc: Arnd Bergmann <[email protected]>
----
drivers/net/spider_net.c | 8 +++++---
drivers/net/spider_net.h | 7 +++----
2 files changed, 8 insertions(+), 7 deletions(-)
Index: linux-2.6.18-mm2/drivers/net/spider_net.c
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.c 2006-10-02 19:06:55.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.c 2006-10-02 19:09:38.000000000 -0500
@@ -707,7 +707,9 @@ spider_net_set_low_watermark(struct spid
descr = descr->next;
cnt++;
}
- if (cnt == 0)
+
+ /* If TX queue is short, don't even bother with interrupts */
+ if (cnt < tx_descriptors/4)
return;
/* Set low-watermark 3/4th's of the way into the queue. */
@@ -716,7 +718,7 @@ spider_net_set_low_watermark(struct spid
for (i=0;i<cnt; i++)
descr = descr->next;
- /* Set the new watermark, clear the old wtermark */
+ /* Set the new watermark, clear the old watermark */
spin_lock_irqsave(&card->tx_chain.lock, flags);
descr->dmac_cmd_status |= SPIDER_NET_DESCR_TXDESFLG;
if (card->low_watermark && card->low_watermark != descr)
@@ -1639,7 +1641,7 @@ spider_net_enable_card(struct spider_net
SPIDER_NET_INT2_MASK_VALUE);
spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
- SPIDER_NET_GDTBSTA);
+ SPIDER_NET_GDTBSTA | SPIDER_NET_GDTDCEIDIS);
}
/**
Index: linux-2.6.18-mm2/drivers/net/spider_net.h
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.h 2006-10-02 19:06:55.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.h 2006-10-02 19:09:38.000000000 -0500
@@ -217,7 +217,8 @@ extern char spider_net_driver_name[];
#define SPIDER_NET_GDTBSTA 0x00000300
#define SPIDER_NET_GDTDCEIDIS 0x00000002
#define SPIDER_NET_DMA_TX_VALUE SPIDER_NET_TX_DMA_EN | \
- SPIDER_NET_GDTBSTA
+ SPIDER_NET_GDTBSTA | \
+ SPIDER_NET_GDTDCEIDIS
#define SPIDER_NET_DMA_TX_FEND_VALUE 0x00030003
/* SPIDER_NET_UA_DESCR_VALUE is OR'ed with the unicast address */
@@ -326,9 +327,7 @@ enum spider_net_int2_status {
SPIDER_NET_GRISPDNGINT
};
-#define SPIDER_NET_TXINT ( (1 << SPIDER_NET_GTTEDINT) | \
- (1 << SPIDER_NET_GDTDCEINT) | \
- (1 << SPIDER_NET_GDTFDCINT) )
+#define SPIDER_NET_TXINT ( (1 << SPIDER_NET_GDTFDCINT) )
/* we rely on flagged descriptor interrupts*/
#define SPIDER_NET_RXINT ( (1 << SPIDER_NET_GDAFDCINT) | \
The module param permsissions should bw read-only, not writable.
Signed-off-by: James K Lewis <[email protected]>
Signed-off-by: Linas Vepstas <[email protected]>
Cc: Arnd Bergmann <[email protected]>
----
drivers/net/spider_net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.18-mm2/drivers/net/spider_net.c
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.c 2006-10-02 19:09:38.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.c 2006-10-02 19:14:48.000000000 -0500
@@ -60,8 +60,8 @@ MODULE_VERSION(VERSION);
static int rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_DEFAULT;
static int tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_DEFAULT;
-module_param(rx_descriptors, int, 0644);
-module_param(tx_descriptors, int, 0644);
+module_param(rx_descriptors, int, 0444);
+module_param(tx_descriptors, int, 0444);
MODULE_PARM_DESC(rx_descriptors, "number of descriptors used " \
"in rx chains");
On Tuesday 03 October 2006 22:57, Linas Vepstas wrote:
> +???????if ((chain->head->next == chain->tail->prev) ||
> +??????? ? (spider_net_get_descr_status(descr) != SPIDER_NET_DESCR_NOT_IN_USE)) {
> ????????????????result = NETDEV_TX_LOCKED;
> ????????????????goto out;
> ????????}
...
> ?out:
> -???????netif_wake_queue(netdev);
> +???????card->netdev_stats.tx_dropped++;
> +???????netif_stop_queue(netdev);
> ????????return result;
> ?}
Hmm, this looks a little strange to me. I would assume that we should not
stop the queue when the device is locked, but only when it is busy.
I would assume though that the fix is to return NETDEV_TX_BUSY instead
of NETDEV_TX_LOCKED in the case above, while the netif_stop_queue()
is correct here.
Arnd <><
On Wed, Oct 04, 2006 at 12:19:42AM +0200, Arnd Bergmann wrote:
> On Tuesday 03 October 2006 22:57, Linas Vepstas wrote:
> > ????????????????result = NETDEV_TX_LOCKED;
>
> Hmm, this looks a little strange to me.
Right. This was left-over cruft from back when.
I'll fix this and resend the whole series tommorrow or friday,
I've got a few more minor performnace tweaks, an implementation
of NETIF_F_SG, and another fix or two, etc.
--linas