Re: [PATCH 2/5] PCI: Use MSI/MSI-X cap cache in pci_msi_check_device()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Apr 4, 2013 at 5:39 AM, Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx> wrote:
> The function pci_msi_check_device() is called while enabling MSI
> or MSI-X interrupts to make sure the PCI device can support MSI
> or MSI-X capability. The patch changes the function for a bit to
> use the cached MSI or MSI-X capability in pci_dev instead of polling
> them from config space.
>
> Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
> ---
>  drivers/pci/msi.c |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 3459bdf..5f51e10 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -772,6 +772,11 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
>         if (!pci_msi_enable || !dev || dev->no_msi)
>                 return -EINVAL;
>
> +       /* Check if the PCI device has MSI or MSI-X capability */
> +       if ((type == PCI_CAP_ID_MSI && !dev->msi_cap) ||
> +           (type == PCI_CAP_ID_MSIX && !dev->msix_cap))
> +               return -EINVAL;

The whole point of this is simplification, so just add "if
(!dev->msi_cap) return -EINVAL" (or "if (!dev->msix_cap)") to the
callers and drop the checking here in pci_msi_check_device().

> +
>         /*
>          * You can't ask to have 0 or less MSIs configured.
>          *  a) it's stupid ..
> @@ -795,9 +800,6 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
>         if (ret)
>                 return ret;
>
> -       if (!pci_find_capability(dev, type))
> -               return -EINVAL;
> -
>         return 0;
>  }
>
> --
> 1.7.5.4
>
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux