[ixp1200] Re: SDK 2 Linux, ...

[Scott C. Karlin]

On Fri, Feb 15, 2002 at 10:10:34AM +0100, Mirko Benz wrote:
> 
> Is there support for the SDK 2.0 version of Linux for IXP12EB?

I don't think so.

> The PCI performance figures from the vera paper are not what I would
> expect.

Can you be more specific?  DMA or PIO?  Which direction?

> Is this really the maximum or what can be tweaked?

I didn't spend much time tweaking the numbers so I'm sure they
can be improved.  My goal was to get representative numbers for
a router application rather than absolute peak numbers.  The
Pentium-to-IXP1200 (with the Pentium as the master) numbers are
probably close to the maximum for our system.

> Would using the I2O unit help?

Probably not.  Remember that we are using the I2O register support
but not any I2O hardware.  (For example, our motherboard did not have
an i960 based I/O processor commonly associated with I2O.)

Also, the Rev B0 IXP1200 chips we were using did not have working
I2O support so we had to simulate this by introducing PCI reads
and writes where we would access the I2O registers and assume that
the registers would have the expected results (i.e., point to the
correct memory frames).  We are now using Rev C0 chips which have
working I2O support; however, we have not re-run our experiments.

Scott