Re: [PATCH] PCI: bus scan adjustments

[Keir Fraser <keir@xen.org>]

On 11/09/2012 12:29, "Jan Beulich" <JBeulich@suse.com> wrote:

> As done elsewhere, the ns16550 code shouldn't look at non-zero
> functions of a device if that isn't multi-function.
> 
> Also both there and in pass-through's _scan_pci_devices() skip looking
> at non-zero functions when the device at function zero doesn't exist.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> Note that to apply cleanly, this has to go on top of the serial console
> improvement series posted earlier.

Acked-by: Keir Fraser <keir@xen.org>

> --- a/xen/drivers/char/ns16550.c
> +++ b/xen/drivers/char/ns16550.c
> @@ -470,21 +470,28 @@ static int
>  pci_uart_config (struct ns16550 *uart, int skip_amt, int bar_idx)
>  {
>      uint32_t bar, len;
> -    int b, d, f;
> +    int b, d, f, nextf;
>  
>      /* NB. Start at bus 1 to avoid AMT: a plug-in card cannot be on bus 0. */
>      for ( b = skip_amt ? 1 : 0; b < 0x100; b++ )
>      {
>          for ( d = 0; d < 0x20; d++ )
>          {
> -            for ( f = 0; f < 0x8; f++ )
> +            for ( f = 0; f < 8; f = nextf )
>              {
> +                nextf = (f || (pci_conf_read16(0, b, d, f, PCI_HEADER_TYPE) &
> +                               0x80)) ? f + 1 : 8;
> +
>                  switch ( pci_conf_read16(0, b, d, f, PCI_CLASS_DEVICE) )
>                  {
>                  case 0x0700: /* single port serial */
>                  case 0x0702: /* multi port serial */
>                  case 0x0780: /* other (e.g serial+parallel) */
>                      break;
> +                case 0xffff:
> +                    if ( !f )
> +                        nextf = 8;
> +                    /* fall through */
>                  default:
>                      continue;
>                  }
> --- a/xen/drivers/passthrough/pci.c
> +++ b/xen/drivers/passthrough/pci.c
> @@ -665,7 +665,11 @@ static int __init _scan_pci_devices(stru
>              for ( func = 0; func < 8; func++ )
>              {
>                  if ( pci_device_detect(pseg->nr, bus, dev, func) == 0 )
> +                {
> +                    if ( !func )
> +                        break;
>                      continue;
> +                }
>  
>                  pdev = alloc_pdev(pseg, bus, PCI_DEVFN(dev, func));
>                  if ( !pdev )
> 
> 
> 
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