releases/6.16.2/acpi-suppress-misleading-spcr-console-message-when-s.patch

From 345d5f283f93963c012799f31a1caf4aa1467d0a Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Fri, 20 Jun 2025 21:13:08 +0800
Subject: ACPI: Suppress misleading SPCR console message when SPCR table is
 absent

From: Li Chen <chenl311@chinatelecom.cn>

[ Upstream commit bad3fa2fb9206f4dcec6ddef094ec2fbf6e8dcb2 ]

The kernel currently alway prints:
"Use ACPI SPCR as default console: No/Yes "

even on systems that lack an SPCR table. This can
mislead users into thinking the SPCR table exists
on the machines without SPCR.

With this change, the "Yes" is only printed if
the SPCR table is present, parsed and !param_acpi_nospcr.
This avoids user confusion on SPCR-less systems.

Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/20250620131309.126555-3-me@linux.beauty
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/kernel/acpi.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index b9a66fc146c9..4d529ff7ba51 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -197,6 +197,8 @@ static int __init acpi_fadt_sanity_check(void)
  */
 void __init acpi_boot_table_init(void)
 {
+	int ret;
+
 	/*
 	 * Enable ACPI instead of device tree unless
 	 * - ACPI has been disabled explicitly (acpi=off), or
@@ -250,10 +252,12 @@ void __init acpi_boot_table_init(void)
 		 * behaviour, use acpi=nospcr to disable console in ACPI SPCR
 		 * table as default serial console.
 		 */
-		acpi_parse_spcr(earlycon_acpi_spcr_enable,
+		ret = acpi_parse_spcr(earlycon_acpi_spcr_enable,
 			!param_acpi_nospcr);
-		pr_info("Use ACPI SPCR as default console: %s\n",
-				param_acpi_nospcr ? "No" : "Yes");
+		if (!ret || param_acpi_nospcr || !IS_ENABLED(CONFIG_ACPI_SPCR_TABLE))
+			pr_info("Use ACPI SPCR as default console: No\n");
+		else
+			pr_info("Use ACPI SPCR as default console: Yes\n");
 
 		if (IS_ENABLED(CONFIG_ACPI_BGRT))
 			acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
-- 
2.39.5