On Thu, Jun 23, 2016 at 11:36:22AM +0100, Lorenzo Pieralisi wrote: > The PCI bios API does not reassign bus resources on systems > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > that would trigger system failures. Nonetheless, PCI bus resources > allocated to PCI bridge and devices must be claimed in order to be > validated and inserted in the kernel resource tree, but the current > code omits the resources claiming and relies on arch specific kludges > to prevent probing failure (ie preventing resources enablement on > PCI_PROBE_ONLY systems). > > Add code to the ARM PCI bios kernel layer that correctly claims bus > resources upon probe on systems that are required to prevent > reassignment after bus enumeration, so that the allocated resources > can be enabled successfully upon PCI device drivers probing, without > resorting to arch back-ends workarounds. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Cc: Russell King <linux@xxxxxxxxxxxxxxx> > --- > Hi Bjorn, > > I put together this patch as requested, I could not test this > specific path but I do not really see how this patch would > affect any existing set-up. > > It completes (and should be inserted as patch 2 or 3 for > bisection reasons) this series: > > https://patchwork.ozlabs.org/patch/632161/ > > Please let me know if that's ok. Yes, this is exactly what I had in mind. Then all the places that use PCI_PROBE_ONLY will make sense when we look at them later. I'll add this to the series on pci/resource. Thanks! > arch/arm/kernel/bios32.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c > index 488545f..1e05d04 100644 > --- a/arch/arm/kernel/bios32.c > +++ b/arch/arm/kernel/bios32.c > @@ -515,7 +515,9 @@ void pci_common_init_dev(struct device *parent, struct hw_pci *hw) > list_for_each_entry(sys, &head, node) { > struct pci_bus *bus = sys->bus; > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > + if (pci_has_flag(PCI_PROBE_ONLY)) { > + pci_bus_claim_resources(bus); > + } else { > struct pci_bus *child; > > /* > -- > 2.6.4 > > -- > 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 -- 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
