Re: [PATCH v10 09/10] PCI: Assign unassigned bus resources in pci_scan_root_bus()
From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Date: 2014-09-12 10:14:26
Also in:
linux-arch, linux-arm-kernel, linux-pci, lkml
On 9/8/2014 8:54 AM, Liviu Dudau wrote:
quoted hunk ↗ jump to hunk
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 <redacted> 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