Re: [PATCH 3/3] net: fs_enet: make rx_copybreak value configurable

Measurement shows that on a MPC8xx running at 132MHz, the optimal
limit is 112:
* 114 bytes packets are processed in 147 TB ticks with higher copybreak
* 114 bytes packets are processed in 148 TB ticks with lower copybreak
* 128 bytes packets are processed in 154 TB ticks with higher copybreak
* 128 bytes packets are processed in 148 TB ticks with lower copybreak
* 238 bytes packets are processed in 172 TB ticks with higher copybreak
* 238 bytes packets are processed in 148 TB ticks with lower copybreak

However it might be different on other processors
and/or frequencies. So it is useful to make it configurable.

Signed-off-by: Christophe Leroy <redacted>
---
 drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c | 8 +++++---
 include/linux/fs_enet_pd.h                            | 1 -
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index addcae6..b59bbf8 100644
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c

@@ -60,6 +60,10 @@ module_param(fs_enet_debug, int, 0);
 MODULE_PARM_DESC(fs_enet_debug,
 		 "Freescale bitmapped debugging message enable value");
 
+static int rx_copybreak = 240;
+module_param(rx_copybreak, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(rx_copybreak, "Receive copy threshold");