Re: [PATCH v3, part2 14/20] PCI, DRM: use hotplug-safe iterators to walk PCI buses

[Bjorn Helgaas <bhelgaas@google.com>]

On Sun, May 26, 2013 at 11:53:11PM +0800, Jiang Liu wrote:
> Enhance DRM drvier to use hotplug-safe iterators to walk PCI buses.
> 
> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
> Cc: David Airlie <airlied@linux.ie>
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  drivers/gpu/drm/drm_fops.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index 429e07d..dc8c40b 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -359,9 +359,11 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
>  			pci_dev_put(pci_dev);
>  		}
>  		if (!dev->hose) {
> -			struct pci_bus *b = pci_bus_b(pci_root_buses.next);
> -			if (b)
> +			struct pci_bus *b = pci_get_next_root_bus(NULL);
> +			if (b) {
>  				dev->hose = b->sysdata;
> +				pci_bus_put(b);
> +			}

This is a gross hack to begin with, and it would be far better to get
rid of the whole "#ifdef __alpha__" block that contains this code.
I can't believe alpha is so special that it needs to do something
that no other arch needs.

>  		}
>  	}
>  #endif
> -- 
> 1.8.1.2
>