[+cc Thierry]
In subject,
PCI: Let pcibios_root_bridge_prepare() access bridge->windows
On Mon, Nov 15, 2021 at 08:08:05AM +0100, Sergio Paracuellos wrote:
> When function 'pci_register_host_bridge()' is called, 'bridge->windows' are
> already available. However this windows are being moved temporarily from
> there. To let 'pcibios_root_bridge_prepare()' to have access to this windows
> move this windows movement after call this function. This is interesting for
> MIPS ralink mt7621 platform to be able to properly set I/O coherence units
> with this information and avoid custom MIPs code in generic PCIe controller
> drivers.
>
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
> ---
> drivers/pci/probe.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 087d3658f75c..372a70efccc6 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -898,8 +898,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>
> bridge->bus = bus;
>
> - /* Temporarily move resources off the list */
> - list_splice_init(&bridge->windows, &resources);
Arnd added this with 37d6a0a6f470 ("PCI: Add
pci_register_host_bridge() interface") [1].
I can't remember why this was done, but we did go to some trouble to
move things around, so there must have been a good reason.
Arnd or Thierry, do you remember?
> bus->sysdata = bridge->sysdata;
> bus->ops = bridge->ops;
> bus->number = bus->busn_res.start = bridge->busnr;
> @@ -925,6 +923,8 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
> if (err)
> goto free;
>
> + /* Temporarily move resources off the list */
> + list_splice_init(&bridge->windows, &resources);
> err = device_add(&bridge->dev);
> if (err) {
> put_device(&bridge->dev);
> --
> 2.33.0
>
[1] https://git.kernel.org/linus/37d6a0a6f470
