[S] Change in coreboot[master]: mb/google/brya/acpi: Don't wait for PG in GPU off sequences

[Nick Vaccaro (Code Review)]

Nick Vaccaro has submitted this change. ( https://review.coreboot.org/c/coreboot/+/76050?usp=email )

Change subject: mb/google/brya/acpi: Don't wait for PG in GPU off sequences
......................................................................

mb/google/brya/acpi: Don't wait for PG in GPU off sequences

When powering rails down, there is no value in waiting for the PG
signal to de-assert. Instead, shut the rails off as quickly as possible
while maintaining a controlled ordering.

BUG=b:288266850
TEST=build and measured delays are gone
Signed-off-by: Tarun Tuli

Change-Id: If31691a7d62b72661fcbacb34e90f3a6adec8134
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76050
Reviewed-by: Eric Lai 
Reviewed-by: Nick Vaccaro 
Tested-by: build bot (Jenkins) 
---
M src/mainboard/google/brya/acpi/power.asl
1 file changed, 3 insertions(+), 11 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Eric Lai: Looks good to me, approved
  Nick Vaccaro: Looks good to me, but someone else must approve

diff --git a/src/mainboard/google/brya/acpi/power.asl b/src/mainboard/google/brya/acpi/power.asl
index 5638e18..a51bcaa 100644
--- a/src/mainboard/google/brya/acpi/power.asl
+++ b/src/mainboard/google/brya/acpi/power.asl
@@ -137,7 +137,6 @@

/* Ramp down PEXVDD */
    CTXS (GPIO_PEXVDD_PWR_EN)
-	GPPL (GPIO_PEXVDD_PG, 0, 20)
 #if CONFIG(BOARD_GOOGLE_AGAH)
    Sleep (10)
 #else
@@ -146,7 +145,6 @@

/* Deassert EN_PPVAR_GPU_NVVDD */
    CTXS (GPIO_NVVDD_PWR_EN)
-	GPPL (NVPG, 0, 20)
    Sleep (2)

/* Assert GPU_PERST_L */
@@ -280,40 +278,34 @@
    CTXS (GPIO_GPU_ALLRAILS_PG)
    Sleep (1)

-	/* Ramp down FBVDD and let rail discharge to <10% */
+	/* Ramp down FBVDD */
 #if CONFIG(BOARD_GOOGLE_AGAH)
    STXS (GPIO_FBVDD_PWR_EN)
 #else
    CTXS (GPIO_FBVDD_PWR_EN)
 #endif
-	GPPL (GPIO_FBVDD_PG, 0, 20)

/* Ramp down PEXVDD and let rail discharge to <10% */
    CTXS (GPIO_PEXVDD_PWR_EN)
-	GPPL (GPIO_PEXVDD_PG, 0, 20)
 #if CONFIG(BOARD_GOOGLE_AGAH)
    Sleep (10)
 #else
    Sleep (3)
 #endif

-	/* Ramp down NVVDD and let rail discharge to <10% */
+	/* Ramp down NVVDD */
    CTXS (GPIO_NVVDD_PWR_EN)
-	GPPL (NVPG, 0, 20)
    Sleep (2)

-	/* Ramp down NV33 and let rail discharge to <10% */
+	/* Ramp down NV33 */
    CTXS (GPIO_NV33_PWR_EN)
-	GPPL (GPIO_NV33_PG, 0, 20)
    Sleep (4)

/* Ramp down 1.8V */
    CTXS (GPEN)
-	GPPL (GPIO_1V8_PG, 0, 20)

/* Ramp down 1.2V rail on boards with support */
    CTXS (GPIO_NV12_PWR_EN)
-	GPPL (GPIO_NV12_PG, 0, 5)

GCOT = Timer