Gianfar - MPC8541 - tx buffer overrun errors

[Joyeau Sylvain]

Hi Shriram,

Try to increase the DEFAULT_TX_RING_SIZE parameter in gianfar.h.
Enabling NAPI mechanism should have no effect on transmission side.

Cheers
--
sj


________________________________

	From:
linuxppc-embedded-bounces+sylvain.joyeau=thomson.net at ozlabs.org
[mailto:linuxppc-embedded-bounces+sylvain.joyeau=thomson.net at ozlabs.org]
On Behalf Of Shriram Janardhan
	Sent: jeudi 6 septembre 2007 03:49
	To: linuxppc-embedded at ozlabs.org
	Subject: Gianfar - MPC8541 - tx buffer overrun errors
	
	
	All,
	 
	I am running 2.6.11 version of the kernel on MPC8541.  Have one
of the TSECs configured at 100Mbps/Full Duplex.  The TSEC MAC is
connected to a Marvell Ethernet switch MAC without any PHY in between.
MAC level flow control is enabled but no pause frames sent or received.
	 
	I see a high number of transmit buffer overrun errors
(tx_fifo_empty errors in the gianfar driver).  I don't have NAPI
enabled.  In addition to other things, I was thinking of enabling NAPI
and see if it helps - is there any downside to it??  Are there any other
parameters that I could tweak to reduce/eliminate the overrun errors??
	 
	Thanks,
	Shriram.
	 

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