diff options
author | kaloz <kaloz@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2011-01-27 12:51:25 +0000 |
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committer | kaloz <kaloz@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2011-01-27 12:51:25 +0000 |
commit | 05448b64c0d737d0e5cd1b3d658058ca14a92b80 (patch) | |
tree | 141750842c67e1e20a9f8ed11ad09789658e3f12 /target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch | |
parent | 0a8698549c7a9d9448ae0c23d3c0eea8f5ef656b (diff) |
[target/leon]: add preliminary LEON support
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25139 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch')
-rw-r--r-- | target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch b/target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch new file mode 100644 index 000000000..3a14eb76d --- /dev/null +++ b/target/linux/leon/patches/020-greth_optimize_gbit_tx_descriptor_handling.patch @@ -0,0 +1,61 @@ +From 544631281bed5cc37b8f2d3a99f44c9d4b97f9a8 Mon Sep 17 00:00:00 2001 +From: Daniel Hellstrom <daniel@gaisler.com> +Date: Wed, 1 Dec 2010 10:07:12 +0100 +Subject: [PATCH] GRETH: GBit transmit descriptor handling optimization + +It is safe to enable all fragments before enabling the first descriptor, +this way all descriptors don't have to be processed twice, added extra +memory barrier. + +Signed-off-by: Daniel Hellstrom <daniel@gaisler.com> +--- + drivers/net/greth.c | 19 ++++++++++--------- + 1 files changed, 10 insertions(+), 9 deletions(-) + +--- a/drivers/net/greth.c ++++ b/drivers/net/greth.c +@@ -512,7 +512,7 @@ greth_start_xmit_gbit(struct sk_buff *sk + greth->tx_skbuff[curr_tx] = NULL; + bdp = greth->tx_bd_base + curr_tx; + +- status = GRETH_TXBD_CSALL; ++ status = GRETH_TXBD_CSALL | GRETH_BD_EN; + status |= frag->size & GRETH_BD_LEN; + + /* Wrap around descriptor ring */ +@@ -549,26 +549,27 @@ greth_start_xmit_gbit(struct sk_buff *sk + + wmb(); + +- /* Enable the descriptors that we configured ... */ +- for (i = 0; i < nr_frags + 1; i++) { +- bdp = greth->tx_bd_base + greth->tx_next; +- greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN); +- greth->tx_next = NEXT_TX(greth->tx_next); +- greth->tx_free--; +- } ++ /* Enable the descriptor chain by enabling the first descriptor */ ++ bdp = greth->tx_bd_base + greth->tx_next; ++ greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN); ++ greth->tx_next = curr_tx; ++ greth->tx_free -= nr_frags + 1; ++ ++ wmb(); + + greth_enable_tx(greth); + + return NETDEV_TX_OK; + + frag_map_error: +- /* Unmap SKB mappings that succeeded */ ++ /* Unmap SKB mappings that succeeded and disable descriptor */ + for (i = 0; greth->tx_next + i != curr_tx; i++) { + bdp = greth->tx_bd_base + greth->tx_next + i; + dma_unmap_single(greth->dev, + greth_read_bd(&bdp->addr), + greth_read_bd(&bdp->stat) & GRETH_BD_LEN, + DMA_TO_DEVICE); ++ greth_write_bd(&bdp->stat, 0); + } + map_error: + if (net_ratelimit()) |