Re: [Linaro-acpi] [PATCH 1/3] ARM64 / PCI / ACPI: Do not return error when a MMCONFIG entry already exist

On 2015年05月21日 06:19, Suravee Suthikulpanit wrote:

During MCFG parsing, the configuration space is added through the following code path:

 -- acpi_parse_mcfg()
  |-- pci_mmconfig_add()
    |-- pci_mmconfig_alloc()

Then, during PCI root creation, it is trying to re-allocating the config space.

 -- acpi_pci_root_add()
  |-- pci_acpi_scan_root()
    |-- acpi_pci_root_create()
      |-- ops->init_info() == pci_acpi_root_init_info()
        |-- pci_add_mmconfig_region()
          |-- pci_mmconfig_lookup()
          |-- pci_mmconfig_alloc()

Therefore, we should be safe to just return if it's already existed.

Signed-off-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com

arch/arm64/kernel/pci.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 5c79f51..3dc82e0 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -157,8 +157,13 @@ static int pci_add_mmconfig_region(struct acpi_pci_root_info *ci) info->mcfg_added = false;

cfg = pci_mmconfig_lookup(seg, info->start_bus);

• if (cfg)

• return -EEXIST;
  

• if (cfg) {

• /* Note: if segment already exist.
  

•  * This should be okay we should
  

•  * simply just return.
  

•  */
  

• return 0;
  

• }

Oh, this is bug, I will squashed your patch to the patch set.

Thanks Hanjun