Subject: 8641D, gianfar driver and BAD Interruptions

From: Régis Odeyé <[email-masked]>
Date: Tue, 17 Nov 2009 17:42:01 +0100

Hello,
On a board based on 8641D, we have BAD interruptions (cat 
/proc/interrupts) which means spurious interruptions seen by the MPIC. 
The number of this BAD ITs are increasing during the life time of the 
system and depending on the ethernet activity.
So this seems to come from the gianfar and we experimented that:
- when we are binding the three interruptions enet_tx, enet_rx and 
enet_err of each interfaces on the same processor, the BAD interruptions 
do not increase any more.
- when we are compiling the driver without the NAPI mode, there is no 
more BAD interruptions at all.
We are playing with a 2.6.25 + some patches Linux kernel.
I did not analyze the errata list of 8641D with this perspective but is 
there anybody who get some inputs about the phenomenon ?
Regards.

-- 
Régis ODEYE

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