Hi George,
+Simon, Stefan
On Fri, Jun 10, 2016 at 1:17 AM, George McCollister george.mccollister@gmail.com wrote:
Does anyone have any ideas on how we might go about disabling functions defined in arch/x86/include/asm/arch-*/acpi on a per board basis? With DT it's trivial to define all of the functions available on an SoC and default them to disabled in the .dtsi, then simply mark them as enabled in the board .dts if the board uses them. I need to disable the internal UART definition for the baytrail board I'm adding since if it's included the off chip UART gets killed when Linux does it's acpi_bus_scan.
Which board are you using? Looks you are using a board that is similar to conga-qeval20-qa3-e3845.
See the TODO comments in arch/x86/include/asm/arch-baytrail/acpi/lpc.asl.
/* Internal UART */ Device (IURT) { Name(_HID, EISAID("PNP0501")) Name(_UID, 1)
Method(_STA, 0, Serialized) { /* * TODO: * * Need to hide the internal UART depending on whether * internal UART is enabled or not so that external * SuperIO UART can be exposed to system. */ Store(1, UI3E) Store(1, UI4E) Store(1, C1EN) Return (STA_VISIBLE) }
To solve this, we need introduce a variable that is set at runtime by U-Boot to tell the ASL codes to hide the internal UART. This is documented in README.x86 below as optional features, but I also mentioned we will need this sooner or later.
Features that are optional: * ACPI global NVS support. We may need it to simplify ASL code logic if utilizing NVS variables. Most likely we will need this sooner or later.
Another place that will need such feature is the memory size. We need tell ASL code to dynamically create the PCI memory space.
Regards, Bin