[S] Change in coreboot[master]: mb/google/brya/acpi: Move dGPU power checks earlier

[Tim Wawrzynczak (Code Review)]

Tim Wawrzynczak has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/67278 )

Change subject: mb/google/brya/acpi: Move dGPU power checks earlier
......................................................................

mb/google/brya/acpi: Move dGPU power checks earlier

Linux always "turns on" a PowerResource when it boots, regardless of
_STA, so the _ON routine should be idempotent. In this case, it all is,
except for the LTR restore, which would restore a value of 0 when _ON is
run the first time, which means that LTR is disabled on the root port
from then on, as the save/restore routines will keep saving/restoring
that 0. THis patch fixes the problem by moving the power checks from
PGON/PGOF to GCOO/GCOI.

BUG=b:244409563
TEST=boot agah and verify that LTR is still enabled on the root port

Signed-off-by: Tim Wawrzynczak 
Change-Id: I4ed78323608eede5b8310598f1f1115497ab2b5b
---
M src/mainboard/google/brya/acpi/power.asl
1 file changed, 33 insertions(+), 13 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/78/67278/1

diff --git a/src/mainboard/google/brya/acpi/power.asl b/src/mainboard/google/brya/acpi/power.asl
index 8940e60..f79a44a 100644
--- a/src/mainboard/google/brya/acpi/power.asl
+++ b/src/mainboard/google/brya/acpi/power.asl
@@ -182,12 +182,6 @@
 /* GCOFF exit sequence */
 Method (PGON, 0, Serialized)
 {
-	If (GPPS == GPU_POWER_STATE_ON)
-	{
-		Printf ("PGON: GPU already on")
-		Return
-	}
-
    Local0 = Timer - GCOT
    If (Local0 < MIN_OFF_TIME_TIMERS)
    {
@@ -234,12 +228,6 @@
 /* GCOFF entry sequence */
 Method (PGOF, 0, Serialized)
 {
-	If (GPPS == GPU_POWER_STATE_OFF)
-	{
-		Printf ("GPU already off")
-		Return
-	}
-
    /* Assert PERST# */
    CTXS (GPIO_GPU_PERST_L)

@@ -278,6 +266,12 @@
 /* GCOFF Out, i.e. full power-on sequence */
 Method (GCOO, 0, Serialized)
 {
+	If (GPPS == GPU_POWER_STATE_ON)
+	{
+		Printf ("PGON: GPU already on")
+		Return
+	}
+
    SRCC (SRCCLK_ENABLE)
    PGON ()
    _SB.PCI0.PEG0.LD23 ()
@@ -310,9 +304,14 @@
 /* GCOFF In, i.e. full power-off sequence */
 Method (GCOI, 0, Serialized)
 {
+	If (GPPS == GPU_POWER_STATE_OFF)
+	{
+		Printf ("GPU already off")
+		Return
+	}
+
    /* Save the PEG port's LTR setting */
    SLTR = LREN
-
    _SB.PCI0.PEG0.DL23 ()
    PGOF ()
    SRCC (SRCCLK_DISABLE)