On Tue, Jan 13, 2009 at 4:20 PM, Bjorn Helgaas <bjorn.helgaas@xxxxxx> wrote:
> The early "dump PCI config space" code skips many multi-function devices.
> This patch fixes that, so it dumps all devices in PCI domain 0.
>
> We should not skip the rest of the device if CLASS_REVISION is 0xffffffff.
> Often multi-function devices have gaps in the function ID space, e.g.,
> 1c.0 and 1c.2 exist but 1c.1 doesn't. The CLASS_REVISION of the non-
> existent 1c.1 function will appear to be 0xffffffff.
>
> We should only look at the HEADER_TYPE of function zero. Often the
> "multi-function" is set in function zero, but not in other functions.
>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
> ---
> arch/x86/pci/early.c | 17 +++++++++--------
> 1 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
> index f6adf2c..db7def6 100644
> --- a/arch/x86/pci/early.c
> +++ b/arch/x86/pci/early.c
> @@ -96,18 +96,19 @@ void early_dump_pci_devices(void)
> for (func = 0; func < 8; func++) {
> u32 class;
> u8 type;
> +
> class = read_pci_config(bus, slot, func,
> PCI_CLASS_REVISION);
> - if (class == 0xffffffff)
> - break;
> -
> - early_dump_pci_device(bus, slot, func);
> + if (class != 0xffffffff)
> + early_dump_pci_device(bus, slot, func);
>
> - /* No multi-function device? */
> - type = read_pci_config_byte(bus, slot, func,
> + if (func == 0) {
> + type = read_pci_config_byte(bus, slot,
> + func,
> PCI_HEADER_TYPE);
> - if (!(type & 0x80))
> - break;
> + if (!(type & 0x80))
> + break;
> + }
> }
> }
> }
it seems you will do extra read_pci_config_byte(,,,_TYPE) when func =
0, and class = 0xffffffff.
YH
>
>
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