Bug #2560
ACPI parser fails to identify COM3 on Tyan motherboard
90%
Description
I have a Tyan S5510GM3NR motherboard that includes a BMC
device with serial-over-lan support. Illumos fails to identify
the COM3 serial port on this board, producing an incomplete
device tree entry like this:
asy (driver not attached)
Hardware properties:
name='compatible' type=string items=1
value='pnpPNP,501'
name='acpi-namespace' type=string items=1
value='\_SB_.PCI0.SBRG.UAR3'
name='model' type=string items=1
value='16550A-compatible COM port'
This does work with a Supermicro motherboard, resulting in
this device entry:
asy, instance #2
System software properties:
name='interrupt-priorities' type=int items=1
value=0000000c
Driver properties:
name='ddi-no-autodetach' type=int items=1 dev=none
value=00000001
Hardware properties:
name='compatible' type=string items=1
value='pnpPNP,501'
name='interrupts' type=int items=1
value=0000000a
name='reg' type=int items=3
value=00000001.000003e8.00000008
name='acpi-namespace' type=string items=1
value='\_SB_.PCI0.SBRG.UAR3'
name='model' type=string items=1
value='16550A-compatible COM port'
Register Specifications:
Bus Type=0x1, Address=0x3e8, Size=0x8
Interrupt Specifications:
Interrupt Priority=0xc (ipl 12), vector=0xa (10)
Device Minor Nodes:
dev=(106,2)
dev_path=/pci@0,0/isa@1f/asy@1,3e8:c
spectype=chr type=minor
dev_link=/dev/ttyc
dev_link=/dev/tty02
dev_link=/dev/term/c
Minor properties:
name='uart' type=string items=1 dev=(106,2)
value='16550A'
dev=(106,131074)
dev_path=/pci@0,0/isa@1f/asy@1,3e8:c,cu
spectype=chr type=minor
dev_link=/dev/ttyd2
dev_link=/dev/cua2
dev_link=/dev/cua/c
The cause seems to be different ACPI DSDT tables. This is a
condensed version of the relevant portion for the Tyan board:
Device (UAR1){
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM2 */
}
StartDependentFnNoPri () {
/* Info on COM3 */
}
StartDependentFnNoPri () {
/* Info on COM4 */
}
EndDependentFn ()
})
}
Device (UAR2){
Name (CRSS, ResourceTemplate () {
/* Info on COM2 */
})
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM2 */
})
}
Device (UAR3){
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM3 */
}
EndDependentFn ()
})
}
This is the same thing for the Supermicro board:
Device (UAR1) {
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM2 */
}
StartDependentFnNoPri () {
/* Info on COM3 */
}
StartDependentFnNoPri () {
/* Info on COM4 */
}
EndDependentFn ()
})
}
Device (UAR2){
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM2 */
}
StartDependentFnNoPri () {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM2 */
}
StartDependentFnNoPri () {
/* Info on COM3 */
}
StartDependentFnNoPri () {
/* Info on COM4 */
}
EndDependentFn ()
})
}
Device (UAR3){
Name (_PRS, ResourceTemplate () {
StartDependentFn (0x00, 0x00) {
/* Info on COM3 */
}
StartDependentFnNoPri () {
/* Info on COM1 */
}
StartDependentFnNoPri () {
/* Info on COM2 */
}
StartDependentFnNoPri () {
/* Info on COM3 */
}
StartDependentFnNoPri () {
/* Info on COM4 */
}
EndDependentFn ()
})
}
I'll attach more complete sections of the DSDT tables.
Files
Updated by Gary Mills over 8 years ago
Here's some information from a couple of other Unix live CDs. Freebsd 9.0 only detects two serial ports on the Tyan system. This is from `devinfo':
uart0 pnpinfo _HID=PNP0501 _UID=1 at handle=\_SB_.PCI0.SBRG.UAR1
Interrupt request lines:
4
I/O ports:
0x3f8-0x3ff
uart1 pnpinfo _HID=PNP0501 _UID=2 at handle=\_SB_.PCI0.SBRG.UAR2
Interrupt request lines:
3
I/O ports:
0x2f8-0x2ff
Ubuntu 12.04, on the other hand, detects three, including the BMC serial port. This is from `dmesg':
[ 3.451274] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 3.538382] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A [ 3.638111] serial8250: ttyS2 at I/O 0x3e8 (irq = 4) is a 16550A [ 3.690245] 00:03: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 3.758356] 00:04: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
Updated by Gary Mills over 8 years ago
- Assignee set to Gary Mills
- % Done changed from 0 to 80
After several months of ACPI debugging with Illumos, I have determined the root cause of this problem: The ACPI DSDT table in the BIOS is faulty. It is missing a _CRS method (current resources) for the UAR3 device (COM3) but does contain a valid _PRS method (possible resources). The DSDT table does contain _CRS methods for UAR1 and UAR2, but not for UAR3. The Illumos kernel only examines current resources at boot time.
I now have a workaround for the Illumos kernel that permits it to work. This consists of a modified acpica driver that uses an ACPI function to examine possible resources when there are no current resources for a device in the ACPI tables. With this workaround, I now have a working serial-over-lan console on my Tyan system for the first time.
I have notified Tyan support of the error in their ACPI tables.
Updated by Gary Mills over 8 years ago
- File acpica-12.7.tar.gz acpica-12.7.tar.gz added
I've attached 32 and 64-bit x86 versions of the acpica driver. These should be installed into /kernel/misc and /kernel/misc/amd64/ respectively. Rename the existing acpica files before you do this. You will also need to update the boot archive before rebooting. Nothing should change unless you are using a Tyan motherboard with a faulty UAR3 definition in the ACPI tables.
Updated by Yuri Pankov over 8 years ago
"Fixing" the upstream source doesn't seem the best way to proceed here, you can report the issue upstream and use updated ACPI tables in the meantime (that's what /boot/acpi/tables/ is for, there are a bit of magic involved to correctly name the files).
Updated by Gary Mills over 8 years ago
- % Done changed from 80 to 90
This change does not modify upstream source, assuming that you mean the Intel ACPICA code. The acpi_enum.c file is the illumos front-end to Intel's code.
Updated by Gordon Ross over 8 years ago
- Status changed from New to Resolved
changeset: 13766:adffc698eaf5
tag: tip
user: Gary Mills <gary_mills@fastmail.fm>
date: Tue Jul 24 18:52:10 2012 -0500
description:
2560 ACPI parser fails to identify COM3 on Tyan motherboard
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Dan McDonald <danmcd@nexenta.com>