DynamicTablesPkg: Fix Ssdt PCI generation comments

The second model of the _PRT object is used. Indeed:
- the interrupts described are not re-configurable
- OSes are aware of the polarity of PCI legacy interrupts,
  so there is no need to accurately describe the polarity.

Also, fix a comment for the CM_ARM_PCI_INTERRUPT_MAP_INFO obj.

Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenerator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenerator.c
index 8509875..c54ae6f 100644
--- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenerator.c
+++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenerator.c
@@ -288,12 +288,6 @@ GeneratePciDeviceInfo (
 

   Cf. ACPI 6.4 specification, s6.2.13 "_PRT (PCI Routing Table)"

 

-  The first model (defining a _CRS object) is used. This is necessary because

-  PCI legacy interrupts are active low and GICv2 SPI interrupts are active

-  high.

-  Even though PCI interrupts cannot be re-routed, only the first model allows

-  to specify the activation state (low/high).

-

   @param [in]       Generator       The SSDT Pci generator.

   @param [in]       CfgMgrProtocol  Pointer to the Configuration Manager

                                     Protocol interface.

@@ -397,6 +391,8 @@ GeneratePrt (
        High word-Device #, Low word-Function #. (for example, device 3,

        function 2 is 0x00030002). To refer to all the functions on a device #,

        use a function number of FFFF).

+

+      Use the second model for _PRT object and describe a hardwired interrupt.

     */

     Status = AmlAddPrtEntry (

                (IrqMapInfo->PciDevice << 16) | 0xFFFF,