Re: [PATCH 8/25] msi: Simplify the msi irq limit policy.

[Rajesh Shah <rajesh.shah@intel.com>]

On Tue, Jun 20, 2006 at 04:28:21PM -0600, Eric W. Biederman wrote:
> Currently we attempt to predict how many irqs we will be
> able to allocate with msi using pci_vector_resources and some
> complicated accounting, and then we only allow each device
> as many irqs as we think are available on average.
> 
> Only the s2io driver even takes advantage of this feature
> all other drivers have a fixed number of irqs they need and
> bail if they can't get them.
> 
> pci_vector_resources is inaccurate if anyone ever frees an irq.
> The whole implmentation is racy.  The current irq limit policy
> does not appear to make sense with current drivers.  So I have
> simplified things.  We can revisit this we we need a more sophisticated
> policy.
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
> ---
>  arch/i386/pci/irq.c |   30 -----------------------------
>  arch/ia64/pci/pci.c |    9 ---------
>  drivers/pci/msi.c   |   53 ++++++++-------------------------------------------
>  drivers/pci/msi.h   |   11 -----------
>  4 files changed, 8 insertions(+), 95 deletions(-)
> 
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 40499c0..772f5b6 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
>  
> @@ -542,11 +540,6 @@ void pci_scan_msi_device(struct pci_dev 
>  {
>  	if (!dev)
>  		return;
> -
> -   	if (pci_find_capability(dev, PCI_CAP_ID_MSIX) > 0)
> -		nr_msix_devices++;
> -	else if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0)
> -		nr_reserved_vectors++;
>  }
Actually, why not just eliminate this function and the
corresponding call from probe.c? It does nothing useful with all
the vector tracking gone from generic MSI code.

Rajesh