[PATCH] ACPI: processor: idle: Add DMI quirk for HA0QING A520

[Munique Feitoza]

On the HA0QING A520 motherboard paired with AMD Ryzen 5000 series
processors (such as the Ryzen 5 5500, Cezanne), entering deep ACPI
C-states (C2/C3 mapped to I/O ports 0x414/0x415, corresponding to
hardware C6) causes severe system instability, random hard freezes,
and memory corruption ('BUG: Bad page state' and list_del corruption
in page allocator / LRU paths) during idle transitions.

Restrict max_cstate to C1 via processor_power_dmi_table for the
HA0QING A520 board to prevent the processor from entering broken deep
C-states and ensure system stability.

Signed-off-by: Munique Feitoza <muniquefeitoz4@xxxxxxxxx>
---
 drivers/acpi/processor_idle.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index e113bcbbb..49768b176 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -105,6 +105,10 @@ static const struct dmi_system_id processor_power_dmi_table[] = {
 	  DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 	  DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 	 (void *)1},
+	{ set_max_cstate, "HA0QING A520", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "HA0QING"),
+	  DMI_MATCH(DMI_BOARD_NAME, "A520") },
+	 (void *)1},
 	{},
 };
 
-- 
2.56.0