[U-Boot] [PATCH][RFC v2] add pci 64 bit prefechable mem support

[FengHua]

> -----Original Messages-----
> From: "Wolfgang Denk" <wd at denx.de>
> Sent Time: 2014-02-14 00:30:24 (Friday)
> To: fenghua at phytium.com.cn
> Cc: u-boot at lists.denx.de, trini at ti.com, albert.u.boot at aribaud.net
> Subject: Re: [PATCH][RFC v2] add pci 64 bit prefechable mem support
> 
> Dear fenghua at phytium.com.cn,
> 
> In message <1392282108-56485-1-git-send-email-fenghua at phytium.com.cn> you wrote:
> > From: David Feng <fenghua at phytium.com.cn>
> > 
> > u-boot did not program the upper 32 bits of prefetchable base and limit
> > in pci bridge config space. I think it's needed when 64 bit address space
> > is used.
> 
> You write "I think it's needed" - is it or not?
> 
> Do you have a specific test case that fails without your patch, and
> works with it?
> 
> Best regards,
> 
> Wolfgang Denk. 
There's no test case now (maybe a few days later I could make a test).
"PCI-to-PCI Bridge Architecture Specification" require that the upper 32 bit of prefetchable space
must be initialized by configuration software. But usually the default value is zero already.
A board using 64 bit pci prefetchable memory space and a pci device with 64 bit prefetchable space
are needed. I think u-boot did not encounter this situation before.

Best Regards,
David