[RFC PATCH] drivers/net/tg3.c: Raise Jumbo Frame MTU to 9216?

From: Joe Perches
Date: Wed Sep 15 2010 - 13:42:03 EST


The TG3 apparently supports 9K frame sizes.

http://www.broadcom.com/collateral/pb/5704C-PB05-R.pdf

Is exactly 9000 a hardware limit?

Should the jumbo frame MTU be raised to 9216 or 9216
less the size of MAC, VLAN, IP and TCP headers?

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 9f6ffff..3727070 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -95,7 +95,7 @@
/* hardware minimum and maximum for a single frame's data payload */
#define TG3_MIN_MTU 60
#define TG3_MAX_MTU(tp) \
- ((tp->tg3_flags & TG3_FLAG_JUMBO_CAPABLE) ? 9000 : 1500)
+ ((tp->tg3_flags & TG3_FLAG_JUMBO_CAPABLE) ? 9216 : 1500)

/* These numbers seem to be hard coded in the NIC firmware somehow.
* You can't change the ring sizes, but you can change where you place


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