Re: [RFC PATCH 1/1] PCI:delay configuration of SRIOV capability

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Sun, 6 Nov 2011 10:33:57 +0800
Ram Pai <linuxram@us.ibm.com> wrote:

>       The SRIOV capability, namely page size and total_vfs of a device are
>       configured during enumeration phase of the device.
>       This can potentially interfere with the PCI operations of the platform,
>       if the IOV capability of the device is not enabled.
> 
>       The following patch postpones the configuration of the IOV capability of the
>       device to a later point, when the IOV capability is explicitly enabled
>       by the device driver.
> 
>       The patch is tested on x86 and power platform.
> 
>       Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
>  drivers/pci/iov.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index b0446dd..c1a6f5c 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -346,6 +346,8 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
>  			return rc;
>  	}
>  
> +	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
> +
>  	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
>  	pci_block_user_cfg_access(dev);
>  	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
> @@ -451,7 +453,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
>  
>  found:
>  	pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
> -	pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, total);
>  	pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
>  	pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
>  	if (!offset || (total > 1 && !stride))
> @@ -464,7 +465,6 @@ found:
>  		return -EIO;
>  
>  	pgsz &= ~(pgsz - 1);
> -	pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
>  
>  	nres = 0;
>  	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {

Anyone want to volunteer a tested-by for this one?

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center