When the pcnet32 adapter is installed in a system with long PCI latency
and the read burst bit is not set, performance on transmission is very
low (under 20Mbit on a 100Mbit link). This patch against 2.6.6-rc1 will
make sure that read and write bursts are enabled. Tested on ppc64 and
ia32.
--- linux-2.6.6-rc1/drivers/net/orig.pcnet32.c Thu Apr 15 11:18:09 2004
+++ linux-2.6.6-rc1/drivers/net/pcnet32.c Thu Apr 15 11:47:00 2004
@@ -1022,10 +1022,11 @@
* starting until the packet is loaded. Strike one for reliability, lose
* one for latency - although on PCI this isnt a big loss. Older chips
* have FIFO's smaller than a packet, so you can't do this.
+ * Turn on BCR18:BurstRdEn and BCR18:BurstWrEn.
*/
if (fset) {
- a->write_bcr(ioaddr, 18, (a->read_bcr(ioaddr, 18) | 0x0800));
+ a->write_bcr(ioaddr, 18, (a->read_bcr(ioaddr, 18) | 0x0860));
a->write_csr(ioaddr, 80, (a->read_csr(ioaddr, 80) & 0x0C00) | 0x0c00);
dxsuflo = 1;
ltint = 1;
--
Don Fry
brazilnut@xxxxxxxxxx
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