Re: [PATCH] starfire reads irq before pci_enable_device.

[Ion Badulescu <ionut@moisil.cs.columbia.edu>]

On Tue, 13 Feb 2001 07:06:44 -0600 (CST), Jeff Garzik <jgarzik@mandrakesoft.mandrakesoft.com> wrote:

> On 12 Feb 2001, Jes Sorensen wrote:
>> In fact one has to look out for this and disable the feature in some
>> cases. On the acenic not disabling Memory Write and Invalidate costs
>> ~20% on performance on some systems.
> 
> And in another message, On Mon, 12 Feb 2001, David S. Miller wrote:
>> 3) The acenic/gbit performance anomalies have been cured
>>    by reverting the PCI mem_inval tweaks.
> 
> Just to be clear, acenic should or should not use MWI?
> 
> And can a general rule be applied here?  Newer Tulip hardware also
> has the ability to enable/disable MWI usage, IIRC.

And so do eepro100 and starfire. On the eepro100 we're enabling MWI 
unconditionally, and on the starfire we disable it unconditionally...

I should probably take a look at acenic's use of PCI_COMMAND_INVALIDATE
to see when it gets activated. Some benchmarking would probably help,
too -- maybe later today.

Ion

-- 
  It is better to keep your mouth shut and be thought a fool,
            than to open it and remove all doubt.