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-rw-r--r--drivers/acpi/processor_idle.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 45a019619e4a..095c8aca141e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -16,6 +16,7 @@
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/sched.h> /* need_resched() */
+#include <linux/sort.h>
#include <linux/tick.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
@@ -384,10 +385,37 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
return;
}
+static int acpi_cst_latency_cmp(const void *a, const void *b)
+{
+ const struct acpi_processor_cx *x = a, *y = b;
+
+ if (!(x->valid && y->valid))
+ return 0;
+ if (x->latency > y->latency)
+ return 1;
+ if (x->latency < y->latency)
+ return -1;
+ return 0;
+}
+static void acpi_cst_latency_swap(void *a, void *b, int n)
+{
+ struct acpi_processor_cx *x = a, *y = b;
+ u32 tmp;
+
+ if (!(x->valid && y->valid))
+ return;
+ tmp = x->latency;
+ x->latency = y->latency;
+ y->latency = tmp;
+}
+
static int acpi_processor_power_verify(struct acpi_processor *pr)
{
unsigned int i;
unsigned int working = 0;
+ unsigned int last_latency = 0;
+ unsigned int last_type = 0;
+ bool buggy_latency = false;
pr->power.timer_broadcast_on_state = INT_MAX;
@@ -411,12 +439,24 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
}
if (!cx->valid)
continue;
+ if (cx->type >= last_type && cx->latency < last_latency)
+ buggy_latency = true;
+ last_latency = cx->latency;
+ last_type = cx->type;
lapic_timer_check_state(i, pr, cx);
tsc_check_state(cx->type);
working++;
}
+ if (buggy_latency) {
+ pr_notice("FW issue: working around C-state latencies out of order\n");
+ sort(&pr->power.states[1], max_cstate,
+ sizeof(struct acpi_processor_cx),
+ acpi_cst_latency_cmp,
+ acpi_cst_latency_swap);
+ }
+
lapic_timer_propagate_broadcast(pr);
return (working);