lkml.org 
[lkml]   [2015]   [Nov]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [Linaro-acpi] [PATCH V1 10/11] pci, acpi: Provide generic way to assign bus domain number.
    From
    Date
    On 03.11.2015 17:10, Lorenzo Pieralisi wrote:
    > On Tue, Oct 27, 2015 at 05:38:41PM +0100, Tomasz Nowicki wrote:
    >> Architectures which support PCI_DOMAINS_GENERIC (like ARM64)
    >> cannot call pci_bus_assign_domain_nr along ACPI PCI host bridge
    >> initialization since this function needs valid parent device reference
    >> to be able to retrieve domain number (aka segment).
    >>
    >> We can omit that blocker and pass down host bridge device via
    >> pci_create_root_bus parameter and then be able to evaluate _SEG method
    >> being in pci_bus_assign_domain_nr.
    >>
    >> Note that _SEG method is optional, therefore _SEG absence means
    >> that all PCI buses belong to domain 0.
    >>
    >> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
    >> ---
    >> drivers/acpi/pci_root.c | 2 +-
    >> drivers/pci/pci.c | 32 +++++++++++++++++++++++++++-----
    >> 2 files changed, 28 insertions(+), 6 deletions(-)
    >>
    >> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
    >> index 850d7bf..e682dc6 100644
    >> --- a/drivers/acpi/pci_root.c
    >> +++ b/drivers/acpi/pci_root.c
    >> @@ -839,7 +839,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
    >>
    >> pci_acpi_root_add_resources(info);
    >> pci_add_resource(&info->resources, &root->secondary);
    >> - bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
    >> + bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops,
    >> sysdata, &info->resources);
    >
    > If I read x86 code correctly, they rely on the first argument to be
    > NULL, I think you would break x86 by doing that, see:
    >
    > arch/x86/pci/acpi.c (pcibios_root_bridge_prepare())
    >
    > By the way, can't we move the code setting up the ACPI_COMPANION
    > to core PCI code and stop relying on sysdata for that ?
    >

    Yes, that will break x86&ia64 but as you said it may be overcome with
    consolidation of ACPI_COMPANION into the core code.

    Tomasz


    \
     
     \ /
      Last update: 2015-11-04 11:21    [W:3.172 / U:0.032 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site