On Wed, Feb 17, 2016 at 8:35 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote: > On 17.02.2016 15:21, Jayachandran Chandrashekaran Nair wrote: >> >> On Wed, Feb 17, 2016 at 7:37 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote: >>> >>> On 17.02.2016 14:44, Jayachandran Chandrashekaran Nair wrote: >>>> >>>> >>>> Tomasz, Lorenzo, >>>> >>>> On Tue, Feb 16, 2016 at 7:23 PM, Tomasz Nowicki<tn@xxxxxxxxxxxx> wrote: >>>>> >>>>> >>>>>> As we now have valid PCI host bridge device reference we can >>>>>> introduce code that is going to find its bus domain number using >>>>>> ACPI _SEG method. >>>>>> >>>>>> Note that _SEG method is optional, therefore _SEG absence means >>>>>> that all PCI buses belong to domain 0. >>>>>> >>>>>> While at it, for the sake of code clarity we put ACPI and DT domain >>>>>> assign methods into the corresponding helpers. >>>> >>>> >>>> In my patchset, I had a slightly different and I think better approach >>>> for >>>> this without calling the _SEG method again. Please see >>>> http://www.spinics.net/lists/arm-kernel/msg478167.html >>>> at the last part >>>> ofhttp://www.spinics.net/lists/arm-kernel/msg478169.html >>> >>> >>> Relying on NULL parent device to make decision on boot method is really >>> ugly >>> way. This may hit us again once we want to obtain another firmware >>> specific >>> info e.g. numa node. IMO we need to fix it this way. >> >> >> I am not relying on NULL there, in the current code parent is NULL >> in case of ACPI, and the check is needed not to crash (unless that >> has changed). > > > This series passes down valid parent, see [PATCH V5 06/15]. > >> >> The main part was the macro acpi_pci_get_segment() and the use >> of acpi_pci_root_info from sysdata to do this. > > > Since we can obtain related firmware specific data from valid parent device > (without defining another accessors), I do not see the point to use sysdata. > Let me know your opinion. In the patch, you use the parent info and call _SEG method again. The segment information is available in the ->root->segment of acpi_pci_root_info if you setup the sysdata like in my patch JC. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
