Re: [PATCH v17 08/10] ACPI / scan: do not enumerate Indirect IO host children
From: John Garry <hidden>
Date: 2018-03-19 10:48:34
Also in:
linux-acpi, linux-arch, linux-pci, lkml
On 19/03/2018 10:30, Rafael J. Wysocki wrote:
On Wednesday, March 14, 2018 7:15:57 PM CET John Garry wrote:quoted
quoted
Through the logical PIO framework systems which otherwise have no IO space access to legacy ISA/LPC devices may access these devices through so-called "indirect IO" method. In this, IO space accesses for non-PCI hosts are redirected to a host LLDD to manually generate the IO space (bus) accesses. Hosts are able to register a region in logical PIO space to map to its bus address range. Indirect IO child devices have an associated host-specific bus address. Special translation is required to map between a logical PIO address for a device and it's host bus address. Since in the ACPI tables the child device IO resources would be the host-specific values, it is required the ACPI scan code should not enumerate these devices, and that this should be the responsibility of the host driver so that it can "fixup" the resources so that they map to the appropriate logical PIO addresses. To avoid enumerating these child devices, we add a check from acpi_device_enumeration_by_parent() as to whether the parent for a device is a member of a known list of "indirect IO" hosts. For now, the HiSilicon LPC host controller ID is added. Signed-off-by: John Garry <redacted> Acked-by: Rafael J. Wysocki <redacted>You have my ACK here already. Since I've ACKed the [7/10] too, I don't think there's anything more I can do about this series and I'm assuming that it will be routed through other trees. Thanks!
Hi Rafael, Thanks for this. Yes, I am working on getting this whole series routed through another tree. Actually I think 7+8 could go separately since there is no build dependency, but I will try to keep the series together. All the best, And thanks again, John