Subject: Re: [PATCH] mark PCI resource with start 0 as unassigned

From: Sergei Shtylyov <[email-masked]>
Date: Mon, 04 Dec 2006 16:27:47 +0300

Hello.

Alan wrote:

>>>>W82C105_IDE: inconsistent baseregs (BIOS) for port 0, skipping

>>>So that needs fixing too, then.

> Both PCI core and IDE interpret a zero length resource as unassigned.

   This is not about 0-length resource, this is about 0-address. Look at 
ide_hwif_confiure() in drivers/ide/setup-pci.c...

> That is probably better than clearing the flags in retrospect.

>>    I'd agree here, that check in the IDE code seems like being too x86 
>>specific. I'm having issues with it as well on MPC85xx/U-Boot...

> setup-pci is for SFF8038i devices. It therefore knows that for assigned
> resources they must be I/O. It also assumes that zero is not a valid I/O
> port just like zero is not a valid IRQ.

    You should know that the IRQ assumption is *not* true even for x86 since 
IRQ0 is and has always been a perfectly valid IRQ (used by PIT).

> Stick a real IDE resource at zero
 > and drivers/ide can't cope.

    Yeah, I've noticed. Unfortunately, a lot of PPC platforms (at least) are 
doing exactly this...

> Alan

WBR, Sergei