[PATCH v6] ACPI: skip IRQ override on AMD Zen platforms

From: Chuanhong Guo <gch981213@gmail.com>
To: linux-acpi@vger.kernel.org
Cc: Tighe Donnelly <tighe.donnelly@protonmail.com>,
	Chuanhong Guo <gch981213@gmail.com>,
	Mario Limonciello <mario.limonciello@amd.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v6] ACPI: skip IRQ override on AMD Zen platforms
Date: Tue, 12 Jul 2022 10:00:58 +0800	[thread overview]
Message-ID: <20220712020058.90374-1-gch981213@gmail.com> (raw)

IRQ override isn't needed on modern AMD Zen systems.
There's an active low keyboard IRQ on AMD Ryzen 6000 and it will stay
this way on newer platforms. This IRQ override breaks keyboards for
almost all Ryzen 6000 laptops currently on the market.

Skip this IRQ override for all AMD Zen platforms because this IRQ
override is supposed to be a workaround for buggy ACPI DSDT and we can't
have a long list of all future AMD CPUs/Laptops in the kernel code.
If a device with buggy ACPI DSDT shows up, a separated list containing
just them should be created.

Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
---
Change sice v5: reworked

 drivers/acpi/resource.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index c2d494784425..510cdec375c4 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -416,6 +416,16 @@ static bool acpi_dev_irq_override(u32 gsi, u8 triggering, u8 polarity,
 {
 	int i;
 
+#ifdef CONFIG_X86
+	/*
+	 * IRQ override isn't needed on modern AMD Zen systems and
+	 * this override breaks active low IRQs on AMD Ryzen 6000 and
+	 * newer systems. Skip it.
+	 */
+	if (boot_cpu_has(X86_FEATURE_ZEN))
+		return false;
+#endif
+
 	for (i = 0; i < ARRAY_SIZE(skip_override_table); i++) {
 		const struct irq_override_cmp *entry = &skip_override_table[i];
 
-- 
2.36.1

