Re: Tigon3 5701 PCI-X recv performance problem

["David S. Miller" <davem@xxxxxxxxxx>]

On Sat, 11 Oct 2003 15:19:21 +0200
Andi Kleen <ak@xxxxxxx> wrote:

> Then just don't set the argument to zero in modules.conf on the 5704cards. 
> That could be even handled somewhere in user space.  Switching over sounds 
> best of course, because the performance with the copying won't be great

There is no "argument" we don't have a variable in the tg3 driver
that determines the "copybreak", it's a hard-coded macro define.

For them it's really easy to know when the 5701 hw bug case is present,
so they can do something like:

        if (len > RX_COPY_THRESHOLD
#ifdef CONFIG_UNALIGNED_EXPENSIVE
            || tp->rx_offset == 2
#endif
            ) {
        ...

And then only their platform and only when the buggy chips are present,
will get the desired change in behavior.