[Qemu-devel] Re: [PATCH] pci: fix pci_find_bus().

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Apr 10, 2010 at 08:48:35AM +0900, Isaku Yamahata wrote:
> Oh I sent out the wrong one. This is the correct one.
> Sorry for noise.
> 
> >From 370c23c837070f78ca5715f032eacbf6747d42fb Mon Sep 17 00:00:00 2001
> Message-Id: <370c23c837070f78ca5715f032eacbf6747d42fb.1270856742.git.yamahata@valinux.co.jp>
> In-Reply-To: <cover.1270856742.git.yamahata@valinux.co.jp>
> References: <cover.1270856742.git.yamahata@valinux.co.jp>
> From: Isaku Yamahata <yamahata@valinux.co.jp>
> Date: Fri, 9 Apr 2010 19:09:35 +0900
> Subject: [PATCH] pci: fix pci_find_bus().
> 
> When looking down child bus, it should look parent bridge's
> bus number, not child bus's.
> 
> Cc: Blue Swirl <blauwirbel@gmail.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
> ---
>  hw/pci.c |    8 ++++----
>  1 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 0dbca17..b6e6bbe 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -1556,10 +1556,10 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
>      }
>  
>      /* try child bus */
> -    QLIST_FOREACH(sec, &bus->child, sibling) {
> -        if (!bus->parent_dev /* pci host bridge */
> -            || (pci_bus_num(sec) <= bus_num &&
> -                bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS]) ) {
> +    if (!bus->parent_dev /* pci host bridge */
> +        || (pci_bus_num(bus) <= bus_num &&

Better use PCI_SECONDARY_BUS here directly, we know parent_dev is
non-NULL.

> +            bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) {
> +        QLIST_FOREACH(sec, &bus->child, sibling) {
>              ret = pci_find_bus(sec, bus_num);
>              if (ret) {
>                  return ret;

What do you think about converting code to loop
as I suggested earlier?

> -- 
> 1.6.6.1
> 
> 
> -- 
> yamahata