On Thu, Dec 17, 2015 at 09:43:29AM +0100, Greg Kurz wrote: > On Thu, 3 Dec 2015 15:53:17 +0100 > Greg Kurz <gk...@linux.vnet.ibm.com> wrote: > > > On Tue, 1 Dec 2015 22:48:38 +0100 > > Thomas Huth <th...@redhat.com> wrote: > > > > > On 30/11/15 11:45, Greg Kurz wrote: > > > > Since commit 1d2d974244c6 "spapr_pci: enumerate and add PCI device > > > > tree", QEMU > > > > populates the PCI device tree in the opposite order compared to SLOF. > > > > > > > > Before 1d2d974244c6: > > > > > > > > Populating /pci@800000020000000 > > > > 00 0000 (D) : 1af4 1000 virtio [ net ] > > > > 00 0800 (D) : 1af4 1001 virtio [ block ] > > > > 00 1000 (D) : 1af4 1009 virtio [ network ] > > > > Populating /pci@800000020000000/unknown-legacy-device@2 > > > > > > > > > > > > 7e5294b8 : /pci@800000020000000 > > > > 7e52b998 : |-- ethernet@0 > > > > 7e52c0c8 : |-- scsi@1 > > > > 7e52c7e8 : +-- unknown-legacy-device@2 ok > > > > > > > > Since 1d2d974244c6: > > > > > > > > Populating /pci@800000020000000 > > > > 00 1000 (D) : 1af4 1009 virtio [ network ] > > > > Populating /pci@800000020000000/unknown-legacy-device@2 > > > > 00 0800 (D) : 1af4 1001 virtio [ block ] > > > > 00 0000 (D) : 1af4 1000 virtio [ net ] > > > > > > > > > > > > 7e5e8118 : /pci@800000020000000 > > > > 7e5ea6a0 : |-- unknown-legacy-device@2 > > > > 7e5eadb8 : |-- scsi@1 > > > > 7e5eb4d8 : +-- ethernet@0 ok > > > > > > > > This behaviour change is not actually a bug since no assumptions should > > > > be > > > > made on DT ordering. But it has no real justification either, other than > > > > being the consequence of the way fdt_add_subnode() inserts new elements > > > > to the front of the FDT rather than adding them to the tail. > > > > > > > > This patch reverts to the historical SLOF ordering by walking PCI > > > > devices in > > > > reverse order. > > > > > > I've applied your patch here locally, and indeed, the device tree looks > > > nicer to me, too, when the nodes are listed in ascending order. > > > > > > Tested-by: Thomas Huth <th...@redhat.com> > > > > > > > > > > Ping ?
Sorry I didn't reply.
I'm still dubious about this. It seems like a fair bit of effort to
restore a behaviour that the client isn't supposed to be relying on
anyway.
Plus, the version with the changed order is already released, so
applying this will mean a second behaviour change.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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