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-rw-r--r--drivers/acpi/processor_idle.c38
-rw-r--r--drivers/net/wireless/ipw2100.c10
2 files changed, 44 insertions, 4 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 71066066d62..0a395fca843 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -38,6 +38,7 @@
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/sched.h> /* need_resched() */
+#include <linux/latency.h>
#include <asm/io.h>
#include <asm/uaccess.h>
@@ -453,7 +454,8 @@ static void acpi_processor_idle(void)
*/
if (cx->promotion.state &&
((cx->promotion.state - pr->power.states) <= max_cstate)) {
- if (sleep_ticks > cx->promotion.threshold.ticks) {
+ if (sleep_ticks > cx->promotion.threshold.ticks &&
+ cx->promotion.state->latency <= system_latency_constraint()) {
cx->promotion.count++;
cx->demotion.count = 0;
if (cx->promotion.count >=
@@ -494,8 +496,10 @@ static void acpi_processor_idle(void)
end:
/*
* Demote if current state exceeds max_cstate
+ * or if the latency of the current state is unacceptable
*/
- if ((pr->power.state - pr->power.states) > max_cstate) {
+ if ((pr->power.state - pr->power.states) > max_cstate ||
+ pr->power.state->latency > system_latency_constraint()) {
if (cx->demotion.state)
next_state = cx->demotion.state;
}
@@ -1009,9 +1013,11 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
seq_printf(seq, "active state: C%zd\n"
"max_cstate: C%d\n"
- "bus master activity: %08x\n",
+ "bus master activity: %08x\n"
+ "maximum allowed latency: %d usec\n",
pr->power.state ? pr->power.state - pr->power.states : 0,
- max_cstate, (unsigned)pr->power.bm_activity);
+ max_cstate, (unsigned)pr->power.bm_activity,
+ system_latency_constraint());
seq_puts(seq, "states:\n");
@@ -1077,6 +1083,28 @@ static const struct file_operations acpi_processor_power_fops = {
.release = single_release,
};
+static void smp_callback(void *v)
+{
+ /* we already woke the CPU up, nothing more to do */
+}
+
+/*
+ * This function gets called when a part of the kernel has a new latency
+ * requirement. This means we need to get all processors out of their C-state,
+ * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
+ * wakes them all right up.
+ */
+static int acpi_processor_latency_notify(struct notifier_block *b,
+ unsigned long l, void *v)
+{
+ smp_call_function(smp_callback, NULL, 0, 1);
+ return NOTIFY_OK;
+}
+
+static struct notifier_block acpi_processor_latency_notifier = {
+ .notifier_call = acpi_processor_latency_notify,
+};
+
int acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device)
{
@@ -1093,6 +1121,7 @@ int acpi_processor_power_init(struct acpi_processor *pr,
"ACPI: processor limited to max C-state %d\n",
max_cstate);
first_run++;
+ register_latency_notifier(&acpi_processor_latency_notifier);
}
if (!pr)
@@ -1164,6 +1193,7 @@ int acpi_processor_power_exit(struct acpi_processor *pr,
* copies of pm_idle before proceeding.
*/
cpu_idle_wait();
+ unregister_latency_notifier(&acpi_processor_latency_notifier);
}
return 0;
diff --git a/drivers/net/wireless/ipw2100.c b/drivers/net/wireless/ipw2100.c
index 6c5add701a6..97937809de0 100644
--- a/drivers/net/wireless/ipw2100.c
+++ b/drivers/net/wireless/ipw2100.c
@@ -163,6 +163,7 @@ that only one external action is invoked at a time.
#include <linux/firmware.h>
#include <linux/acpi.h>
#include <linux/ctype.h>
+#include <linux/latency.h>
#include "ipw2100.h"
@@ -1697,6 +1698,11 @@ static int ipw2100_up(struct ipw2100_priv *priv, int deferred)
return 0;
}
+ /* the ipw2100 hardware really doesn't want power management delays
+ * longer than 175usec
+ */
+ modify_acceptable_latency("ipw2100", 175);
+
/* If the interrupt is enabled, turn it off... */
spin_lock_irqsave(&priv->low_lock, flags);
ipw2100_disable_interrupts(priv);
@@ -1849,6 +1855,8 @@ static void ipw2100_down(struct ipw2100_priv *priv)
ipw2100_disable_interrupts(priv);
spin_unlock_irqrestore(&priv->low_lock, flags);
+ modify_acceptable_latency("ipw2100", INFINITE_LATENCY);
+
#ifdef ACPI_CSTATE_LIMIT_DEFINED
if (priv->config & CFG_C3_DISABLED) {
IPW_DEBUG_INFO(": Resetting C3 transitions.\n");
@@ -6534,6 +6542,7 @@ static int __init ipw2100_init(void)
ret = pci_register_driver(&ipw2100_pci_driver);
+ set_acceptable_latency("ipw2100", INFINITE_LATENCY);
#ifdef CONFIG_IPW2100_DEBUG
ipw2100_debug_level = debug;
driver_create_file(&ipw2100_pci_driver.driver,
@@ -6554,6 +6563,7 @@ static void __exit ipw2100_exit(void)
&driver_attr_debug_level);
#endif
pci_unregister_driver(&ipw2100_pci_driver);
+ remove_acceptable_latency("ipw2100");
}
module_init(ipw2100_init);