On Sat, Jan 14, 2017 at 10:56:54AM +0800, Hanjun Guo wrote:

Hi Lorenzo,

On 2017/1/13 18:21, Lorenzo Pieralisi wrote:

quoted

On Wed, Jan 11, 2017 at 11:06:39PM +0800, Hanjun Guo wrote:

quoted

With the preparation of platform msi support and interrupt producer
in DSDT, we can add mbigen ACPI support now.

We are using _PRS methd to indicate number of irq pins instead
of num_pins in DT to avoid _DSD usage in this case.

For mbi-gen,
    Device(MBI0) {
          Name(_HID, "HISI0152")
          Name(_UID, Zero)
          Name(_CRS, ResourceTemplate() {
                  Memory32Fixed(ReadWrite, 0xa0080000, 0x10000)
          })

          Name (_PRS, ResourceTemplate() {
		  Interrupt(ResourceProducer,...) {12,14,....}

I still do not understand why you are using _PRS for this, I think
the MBIgen configuration is static and if it is so the Interrupt
resource should be part of the _CRS unless there is something I am
missing here.

Sorry for not clear in the commit message. MBIgen is an interrupt producer
which produces irq resource to devices connecting to it, and MBIgen itself
don't consume wired interrupts.

That's why you mark it as ResourceProducer, but that's not a reason to
put it in the _PRS instead of _CRS.

IIUC _PRS is there to provide a way to define the possible resource
settings of a _configurable_ device (ie programmable) so that the actual
resource value you would programme with a call to its _SRS is sane (ie
the OS has a way, through the _PRS, to detect what possible resource
settings are available for the device).

I think Rafael has more insights into how the _PRS is used on x86
systems so I would ask his point of view here before merrily merging
this code.

Also devices connecting MBIgen may not consume all the interrupts produced
by MBIgen, for example, MBIgen may produce 128 interrupts but only half of
them are currently used, so _PRS here means "provide interrupt resources
may consumed by devices connecting to it".

See above.

Lorenzo