[M] Change in coreboot[master]: mb/google/brya: Don't add MPTS to both DSDT and SSDT

[Reka Norman (Code Review)]

Reka Norman has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/70146 )

Change subject: mb/google/brya: Don't add MPTS to both DSDT and SSDT
......................................................................

mb/google/brya: Don't add MPTS to both DSDT and SSDT

CB:65488 started unconditionally adding MPTS to the SSDT. On variants
with HAVE_WWAN_POWER_SEQUENCE selected, MPTS is already added to the
DSDT via wwan_power.asl. The duplicate definition results in a kernel
error:
ERR kernel: [    0.109237] ACPI BIOS Error (bug): Failure creating named object [_SB.MPTS], AE_ALREADY_EXISTS (20210730/dswload2-327)
ERR kernel: [    0.109242] ACPI Error: AE_ALREADY_EXISTS, During name lookup/catalog (20210730/psobject-220)

Don't add MPTS to the SSDT if HAVE_WWAN_POWER_SEQUENCE is selected.
There are no variants which use both, so this should only result in
empty MPTS methods being removed.

BUG=b:260380268
TEST=On pujjo, the SSDT no longer contains an empty MPTS method, there's
no kernel error, and the WWAN power-off sequence is met.

Change-Id: I9f411aae81ea87aa9c8fc7754c3709e398771a32
Signed-off-by: Reka Norman 
---
M src/mainboard/google/brya/mainboard.c
1 file changed, 56 insertions(+), 12 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/46/70146/1

diff --git a/src/mainboard/google/brya/mainboard.c b/src/mainboard/google/brya/mainboard.c
index 4e0cf08..7c51a00 100644
--- a/src/mainboard/google/brya/mainboard.c
+++ b/src/mainboard/google/brya/mainboard.c
@@ -132,6 +132,36 @@
    	acpigen_emit_namestring(acpi_device_path_join(parent, "PGPR._OFF"));
 }

+static void mainboard_generate_mpts(void)
+{
+	const struct device *wwan = DEV_PTR(rp6_wwan);
+	const struct device *dgpu = DEV_PTR(dgpu);
+
+	/*
+	 * If HAVE_WWAN_POWER_SEQUENCE is selected, MPTS will be added to the
+	 * DSDT via wwan_power.asl. We can't add MPTS to the SSDT as well,
+	 * since the duplicate definition will result in a kernel error.
+	 *
+	 * This special case can be removed in the future if the power-off
+	 * sequences for all WWAN devices used on brya are moved to the SSDT.
+	 */
+	if (CONFIG(HAVE_WWAN_POWER_SEQUENCE)) {
+		if (wwan || dgpu)
+			printk(BIOS_ERR, "Cannot include MPTS in both DSDT and SSDT\n");
+		return;
+	}
+
+	acpigen_write_scope("\_SB");
+	acpigen_write_method_serialized("MPTS", 1);
+	if (wwan)
+		mainboard_generate_wwan_shutdown(wwan);
+	if (dgpu)
+		mainboard_generate_dgpu_shutdown(dgpu);
+
+	acpigen_write_method_end(); /* Method */
+	acpigen_write_scope_end(); /* Scope */
+}
+
 static void mainboard_generate_s0ix_hook(void)
 {
    acpigen_write_if_lequal_op_int(ARG0_OP, 1);
@@ -151,18 +181,7 @@

static void mainboard_fill_ssdt(const struct device *dev)
 {
-	const struct device *wwan = DEV_PTR(rp6_wwan);
-	const struct device *dgpu = DEV_PTR(dgpu);
-
-	acpigen_write_scope("\_SB");
-	acpigen_write_method_serialized("MPTS", 1);
-	if (wwan)
-		mainboard_generate_wwan_shutdown(wwan);
-	if (dgpu)
-		mainboard_generate_dgpu_shutdown(dgpu);
-
-	acpigen_write_method_end(); /* Method */
-	acpigen_write_scope_end(); /* Scope */
+	mainboard_generate_mpts();

/* for variant to fill additional SSDT */
    variant_fill_ssdt(dev);