Always zero test in arch/i386/pci/mmconfig-shared.c

Always zero test in arch/i386/pci/mmconfig-shared.c

[Scott Ashcroft]

I don't think it makes any change to subsequent flow but the code in 
pci_mmcfg_check_hostbridge is:

pci_mmcfg_config_num = 0;

...

if (name) {
	printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
	       name, pci_mmcfg_config_num ? "with" : "without");
}

So it will always prints "without".

I'd make a patch but I'm not sure what this fix is. Just drop the test, 
the printk or make it say "which might possibly have"?

Cheers,
Scott

Re: Always zero test in arch/i386/pci/mmconfig-shared.c

[Robert Hancock]

Scott Ashcroft wrote:
> I don't think it makes any change to subsequent flow but the code in 
> pci_mmcfg_check_hostbridge is:
> 
> pci_mmcfg_config_num = 0;
> 

You missed this code:

name = pci_mmcfg_probes[i].probe();

This calls one of the probe functions above, which will set 
pci_mmcfg_config_num to something else, as with the name variable. It 
may set the name but not the config num, if the chipset is recognized 
but MMCONFIG isn't enabled, etc.

> 
> if (name) {
>     printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
>            name, pci_mmcfg_config_num ? "with" : "without");
> }
> 
> So it will always prints "without".
> 
> I'd make a patch but I'm not sure what this fix is. Just drop the test, 
> the printk or make it say "which might possibly have"?
> 
> Cheers,
> Scott

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

Re: Always zero test in arch/i386/pci/mmconfig-shared.c

[Scott Ashcroft]

Robert Hancock wrote:
  > You missed this code:
> 
> name = pci_mmcfg_probes[i].probe();
> 
> This calls one of the probe functions above, which will set 
> pci_mmcfg_config_num to something else, as with the name variable. It 
> may set the name but not the config num, if the chipset is recognized 
> but MMCONFIG isn't enabled, etc.

Obvious now you've pointed it out. Bit of of a weird way to do things.
I might brew up a patch which adds the names to the 
pci_mmcfg_hostbridge_probe struct, since they appear to be always 
returned if the probe function is called, and make the probe functions 
return the config num.

Cheers,
Scott