Re: Addressing PCI memory

[Jeff Garzik <jgarzik@mandrakesoft.com>]

Gabriel Paubert wrote:
>
> On Tue, 15 May 2001, Amelia De Vivo wrote:
>
> >
> > Hi all, I'm trying to write a driver for a 64 bit PCI device. Something like
> > this works well under i386 Linux, but it doesn't work at all for Linux
> > 2.2.15 by Yellow Dog:
> >
> >     struct pci_dev *dev = NULL;
> >     dev = pci_find_device(vendor, device, dev);
> >     pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &cards[0].addr0);
>
> First, use the resource in the dev structure, they do not necessarily
> correspond to the value read from the base, even on Intel BTW.
>
>         cards[0].addr0 = dev->resources[0].start
>
> don't even need to mask the address bits...

correct.

Though note it is highly encouraged to use
pci_resource_{start,end,len,flags} helpers.  That makes it transparent
to port code to earlier kernels, and IMHO makes the code easier to read.

--
Jeff Garzik      | Game called on account of naked chick
Building 1024    |
MandrakeSoft     |

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