On Tuesday, April 3, 2018 4:52:24 PM CEST Mika Westerberg wrote:
> There is a sanity checker in the end of pci_scan_child_bus_extend() that
> tries to detect badly configured bridges. For example given the below
> topology:
>
> +-1b.0-[01-39]----00.0-[02-3a]--+-00.0-[03]----00.0
> +-01.0-[04-39]--
> \-02.0-[3a]----00.0
>
> The sanity checker notices this and logs following messages:
>
> pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:02 [bus 02-39]
> pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:01 [bus 01-39]
>
> This is not really helpful to users and the information above is not
> even correct (0000:02 is a bus not bridge). Make this a bit more
> understandable by changing the sanity checker to log following message
> in place of the above two messages:
>
> pci 0000:02:02.0: devices behind bridge are unusable because we cannot assign [bus 3a] for them
FWIW, I prefer to use passive voice in messages, like
devices behind bridge are unusable, because [bus 3a] cannot be assigned for them
> While there update the comment on top of the sanity checker block to
> make it clear that it is not only restricted to CardBus.
>
> Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/probe.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 079eea6680bb..70b07a0e00b8 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1175,20 +1175,16 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
> (is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
> pci_domain_nr(bus), child->number);
>
> - /* Has only triggered on CardBus, fixup is in yenta_socket */
> + /* Check that all devices are accessible */
> while (bus->parent) {
> if ((child->busn_res.end > bus->busn_res.end) ||
> (child->number > bus->busn_res.end) ||
> (child->number < bus->number) ||
> (child->busn_res.end < bus->number)) {
> - dev_info(&child->dev, "%pR %s hidden behind%s bridge %s %pR\n",
> - &child->busn_res,
> - (bus->number > child->busn_res.end &&
> - bus->busn_res.end < child->number) ?
> - "wholly" : "partially",
> - bus->self->transparent ? " transparent" : "",
> - dev_name(&bus->dev),
> - &bus->busn_res);
> + dev_info(&dev->dev,
> + "devices behind bridge are unusable because we cannot assign %pR for them\n",
> + &child->busn_res);
> + break;
> }
> bus = bus->parent;
> }
>
