[PATCH v3] efifb: avoid reconfiguration of BAR that covers the framebuffer

[Ard Biesheuvel]

On 23 April 2017 at 02:45, Yinghai Lu <yinghai at kernel.org> wrote:
> On Mon, Apr 10, 2017 at 06:29:27PM +0100, Ard Biesheuvel wrote:
>>  /*
>> @@ -208,8 +208,8 @@ struct pci_bus *pci_acpi_scan_root(struct
>> acpi_pci_root *root)
>>         if (!bus)
>>                 return NULL;
>>
>> -       pci_bus_size_bridges(bus);
>> -       pci_bus_assign_resources(bus);
>> +       pci_assign_unassigned_root_bus_resources(bus);
>> +       pci_bus_claim_resources(bus);
>>
>>         list_for_each_entry(child, &bus->children, node)
>>                 pcie_bus_configure_settings(child);
>>
>
> looks like those two lines are reversed. you should use:
>                 pcibios_resource_survey_bus(bus);
>                 pci_assign_unassigned_root_bus_resources(bus);
>
> please check x86 pcibios_resource_survey_bus() definition in
>         arch/x86/pci/i386.c
>
> but pci_bus_claim_resources() should work too.
>

Thanks Yinghai

pcibios_resource_survey_bus() is actually an empty function on arm64,
but I guess that is where logic should go that checks the state of the
BARs before trying to claim anything?