diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 40 |
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); |