https://bugzilla.kernel.org/show_bug.cgi?id=63581
Bjorn Helgaas <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- Assignee|[email protected] |acpi_config-other@kernel-bu | |gs.osdl.org --- Comment #2 from Bjorn Helgaas <[email protected]> --- The question here is how to apply _TRA to I/O port space descriptors in _CRS. We currently handle these descriptors ad hoc in add_window() (for ia64, where we do handle _TRA) and in setup_resource() (for x86, where we don't do anything with _TRA). Lan's patch [1] applies _TRA in the generic acpi_dev_resource_address_space(), and another patch [2] converts ia64 from the ad hoc handling to the generic handling. The problem is that the ia64 code handles _TRA differently than [1] does. My proposal is that [1] should be modified to skip _TRA when the _TTP ("I/O to Memory Translation") bit is set. Here's a sample I/O port space descriptor from the acpidump in comment #1: QWORD Address Space Descriptor: Type: I/O Flags: Sparse, Translate, ISA I/O addresses, Non-ISA I/O addresses GRA: 0x0000000000000000 MIN: 0x0000000000000000 MAX: 0x000000000000ffff TRA: 0x00000400d0000000 LEN: 0x0000000000010000 This window is memory on the upstream side and the host bridge converts it to I/O port space (PCI bus I/O ports 0x0000-0xffff) on the downstream side. The HP BIOS encodes the base memory address on the upstream side in _TRA. The ACPI spec isn't very explicit about how to handle this, but I think the HP interpretation is reasonable and I'm not aware of any conflicting implementations, so I think we should adopt it. [1] http://lkml.kernel.org/r/[email protected] [2] http://lkml.kernel.org/r/[email protected] -- You are receiving this mail because: You are watching the assignee of the bug. ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ acpi-bugzilla mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
