diff options
| author | Willy Tarreau <w@1wt.eu> | 2020-10-11 12:09:44 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-10-14 02:57:12 +0300 |
| commit | 0a4e9ce17ba77847e5a9f87eed3c0ba46e3f82eb (patch) | |
| tree | 9688ac73260eb4cf890da91e3e0e4cfab7e91aa6 /drivers/net/ethernet/cadence/macb.h | |
| parent | 73d7422813839bbcae3dd28ff0d3c48d916e0b57 (diff) | |
| download | linux-0a4e9ce17ba77847e5a9f87eed3c0ba46e3f82eb.tar.xz | |
macb: support the two tx descriptors on at91rm9200
The at91rm9200 variant used by a few chips including the MSC313 supports
two Tx descriptors (one frame being serialized and another one queued).
However the driver only implemented a single one, which adds a dead time
after each transfer to receive and process the interrupt and wake the
queue up, preventing from reaching line rate.
This patch implements a very basic 2-deep queue to address this limitation.
The tests run on a Breadbee board equipped with an MSC313E show that at
1 GHz, HTTP traffic on medium-sized objects (45kB) was limited to exactly
50 Mbps before this patch, and jumped to 76 Mbps with this patch. And tests
on a single TCP stream with an MTU of 576 jump from 10kpps to 15kpps. With
1500 byte packets it's now possible to reach line rate versus 75 Mbps
before.
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20201011090944.10607-4-w@1wt.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/cadence/macb.h')
| -rw-r--r-- | drivers/net/ethernet/cadence/macb.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h index 4c4672ff66a3..5de47f6fde5a 100644 --- a/drivers/net/ethernet/cadence/macb.h +++ b/drivers/net/ethernet/cadence/macb.h @@ -1209,6 +1209,8 @@ struct macb { /* AT91RM9200 transmit queue (1 on wire + 1 queued) */ struct macb_tx_skb rm9200_txq[2]; + unsigned int rm9200_tx_tail; + unsigned int rm9200_tx_len; unsigned int max_tx_length; u64 ethtool_stats[GEM_STATS_LEN + QUEUE_STATS_LEN * MACB_MAX_QUEUES]; |