On Mon, Oct 02, 2017 at 06:28:44PM +0100, Lorenzo Pieralisi wrote: > commit f6810c15cf97 ("iommu/arm-smmu: Clean up early-probing > workarounds") removed kernel code that was allowing to initialize > and probe the SMMU devices early (ie earlier than PCI devices, through > linker script callback entries) in the boot process because it was not > needed any longer in that the SMMU devices/drivers now support deferred > probing. > > Since the SMMUs probe routines are also in charge of requesting global > PCI ACS kernel enablement, commit f6810c15cf97 ("iommu/arm-smmu: Clean > up early-probing workarounds") also postponed PCI ACS enablement to > SMMUs devices probe time, which is too late given that PCI devices needs > to detect if PCI ACS is enabled to init the respective capability > through the following call path: > > pci_device_add() > -> pci_init_capabilities() > -> pci_enable_acs() > > Add code in the ACPI IORT SMMU platform devices initialization path > (that is called before ACPI PCI enumeration) to detect if there > exists firmware mappings to map root complexes ids to SMMU ids > and if so enable ACS for the system. > > Fixes: f6810c15cf97 ("iommu/arm-smmu: Clean up early-probing > Signed-workarounds") > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Cc: Sudeep Holla <sudeep.holla@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Zhou Wang <wangzhou1@xxxxxxxxxxxxx> > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Queued for 4.14-rc4. Thanks. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html