de2104x: support for systems lacking cache coherence
Add a configurable Descriptor Skip Length for systems that lack cache
coherence.
(akpm: I think this should be done as a module parameter, not a
compile-tinme option)
Signed-off-by: Risto Suominen <Risto.Suominen@gmail.com>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tulip/Kconfig b/drivers/net/tulip/Kconfig
index d913405..1cc8cf4 100644
--- a/drivers/net/tulip/Kconfig
+++ b/drivers/net/tulip/Kconfig
@@ -27,6 +27,18 @@
To compile this driver as a module, choose M here. The module will
be called de2104x.
+config DE2104X_DSL
+ int "Descriptor Skip Length in 32 bit longwords"
+ depends on DE2104X
+ range 0 31
+ default 0
+ help
+ Setting this value allows to align ring buffer descriptors into their
+ own cache lines. Value of 4 corresponds to the typical 32 byte line
+ (the descriptor is 16 bytes). This is necessary on systems that lack
+ cache coherence, an example is PowerMac 5500. Otherwise 0 is safe.
+ Default is 0, and range is 0 to 31.
+
config TULIP
tristate "DECchip Tulip (dc2114x) PCI support"
depends on PCI