Re: Pressing the power button causes the device to freeze completely

[Rafael J. Wysocki]

On Tuesday, April 28, 2026 9:11:34 PM CEST Evgeny Sagatov wrote:
> Yes, the PC froze when I pressed the power button.

Well, in that case, let's try to serialize all accesses to I/O ports
used in the ACPI code.

The patch below replaces the previous one, please give it a go.

---
 drivers/acpi/osl.c             |    6 ++++++
 drivers/cpufreq/acpi-cpufreq.c |    4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -664,6 +664,8 @@ u64 acpi_os_get_timer(void)
 		(ACPI_100NSEC_PER_SEC / HZ);
 }
 
+static DEFINE_RAW_SPINLOCK(acpi_os_port_lock);
+
 acpi_status acpi_os_read_port(acpi_io_address port, u32 *value, u32 width)
 {
 	u32 dummy;
@@ -682,6 +684,8 @@ acpi_status acpi_os_read_port(acpi_io_ad
 	else
 		value = &dummy;
 
+	guard(raw_spinlock_irqsave)(&acpi_os_port_lock);
+
 	if (width <= 8) {
 		*value = inb(port);
 	} else if (width <= 16) {
@@ -703,6 +707,8 @@ acpi_status acpi_os_write_port(acpi_io_a
 	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
 		return AE_NOT_IMPLEMENTED;
 
+	guard(raw_spinlock_irqsave)(&acpi_os_port_lock);
+
 	if (width <= 8) {
 		outb(value, port);
 	} else if (width <= 16) {
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -913,7 +913,9 @@ static int acpi_cpufreq_cpu_init(struct
 	data->resume = 1;
 
 	policy->fast_switch_possible = !acpi_pstate_strict &&
-		!(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
+		(!policy_is_shared(policy) ||
+		 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) &&
+		perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO;
 
 	if (perf->states[0].core_frequency * 1000 != freq_table[0].frequency)
 		pr_warn(FW_WARN "P-state 0 is not max freq\n");