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authorMike Loptien <mike.loptien@se-eng.com>2013-03-15 10:53:40 -0600
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-03-15 19:39:35 +0100
commit26855fc70b05cf0294cbe3d5f2195bfb95806780 (patch)
tree692015600436e0859c796ae045b999cc8c5b37d1 /src/mainboard/amd/union_station
parentc4dfae835f956df8ebc2d4da62fb05ec3772cda1 (diff)
AMD Fam14 DSDT: Add secondary bus range to PCI0
Adding the 'WordBusNumber' macro to the PCI0 CRES ResourceTemplate in the Persimmon DSDT. This sets up the bus number for the PCI0 device and the secondary bus number in the CRS method. This change came in response to a 'dmesg' error which states: '[FIRMWARE BUG]: ACPI: no secondary bus range in _CRS' By adding the 'WordBusNumber' macro, ACPI can set up a valid range for the PCIe downstream busses, thereby relieving the Linux kernel from "guessing" the valid range based off _BBN or assuming [0-0xFF]. The Linux kernel code that checks this bus range is in `drivers/acpi/pci_root.c`. PCI busses can have up to 256 secondary busses connected to them via a PCI-PCI bridge. However, these busses do not have to be sequentially numbered, so leaving out a section of the range (eg. allowing [0-0x7F]) will unnecessarily restrict the downstream busses. This is the same change as made to Persimmon with change-id I44f22: http://review.coreboot.org/#/c/2592/ Change-Id: I9017a7619b3b17e0e95ad0fe46d0652499289b00 Signed-off-by: Mike Loptien <mike.loptien@se-eng.com> Reviewed-on: http://review.coreboot.org/2735 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/mainboard/amd/union_station')
-rw-r--r--src/mainboard/amd/union_station/dsdt.asl16
1 files changed, 16 insertions, 0 deletions
diff --git a/src/mainboard/amd/union_station/dsdt.asl b/src/mainboard/amd/union_station/dsdt.asl
index da6f266677..1d2435c0b6 100644
--- a/src/mainboard/amd/union_station/dsdt.asl
+++ b/src/mainboard/amd/union_station/dsdt.asl
@@ -1478,6 +1478,22 @@ DefinitionBlock (
} /* end Ac97modem */
Name(CRES, ResourceTemplate() {
+ /* Set the Bus number and Secondary Bus number for the PCI0 device
+ * The Secondary bus range for PCI0 lets the system
+ * know what bus values are allowed on the downstream
+ * side of this PCI bus if there is a PCI-PCI bridge.
+ * PCI busses can have 256 secondary busses which
+ * range from [0-0xFF] but they do not need to be
+ * sequential.
+ */
+ WordBusNumber (ResourceProducer, MinFixed, MaxFixed, PosDecode,
+ 0x0000, /* address granularity */
+ 0x0000, /* range minimum */
+ 0x00FF, /* range maximum */
+ 0x0000, /* translation */
+ 0x0100, /* length */
+ ,, PSB0) /* ResourceSourceIndex, ResourceSource, DescriptorName */
+
IO(Decode16, 0x0CF8, 0x0CF8, 1, 8)
WORDIO(ResourceProducer, MinFixed, MaxFixed, PosDecode, EntireRange,