Messages in this thread | | | Date | Fri, 12 Sep 2014 05:13:51 -0500 | From | Suravee Suthikulpanit <> | Subject | Re: [PATCH v10 09/10] PCI: Assign unassigned bus resources in pci_scan_root_bus() |
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On 9/8/2014 8:54 AM, Liviu Dudau wrote: > If the firmware has not assigned all the bus resources and > we are not just probing the PCIe busses, it makes sense to > assign the unassigned resources in pci_scan_root_bus(). > > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> > Cc: Rob Herring <robh+dt@kernel.org> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> > --- > drivers/pci/probe.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index ef891d2..508cf61 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1953,6 +1953,9 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, > if (!found) > pci_bus_update_busn_res_end(b, max); > > + if (!pci_has_flag(PCI_PROBE_ONLY)) > + pci_assign_unassigned_bus_resources(b); > + > pci_bus_add_devices(b); > return b; > } >
Liviu,
Besides the check for PCI_PROBE_ONLY here, I think we also need to avoid calling "pci_enable_resources()" in the "driver/pci/pci.c: pcibios_enable_device()" for PCI_PROBE_ONLY mode since the resource is not assigned by Linux. Otherwise, the "drivers/pci/setup-res.c: pci_enable_resource()" would fail w/ error:
can't enable device: BAR ..... not assigned
Actually, in "arch/arm/kernel/bios32.c:", the weak "pcibios_enable_device()" function also has the check for PCI_PROBE_ONLY mode before calling pci_enable_resources().
Thanks,
Suravee
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