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path: root/drivers/acpi/processor_idle.c
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Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c57
1 files changed, 9 insertions, 48 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index ae0010821ce3..7eab733ae96e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -241,26 +241,6 @@ acpi_processor_power_activate(struct acpi_processor *pr,
old->promotion.count = 0;
new->demotion.count = 0;
- /* Cleanup from old state. */
- if (old) {
- switch (old->type) {
- case ACPI_STATE_C3:
- /* Disable bus master reload */
- if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
- acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
- break;
- }
- }
-
- /* Prepare to use new state. */
- switch (new->type) {
- case ACPI_STATE_C3:
- /* Enable bus master reload */
- if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
- acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
- break;
- }
-
pr->power.state = new;
return;
@@ -1121,7 +1101,6 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
" for C3 to be enabled on SMP systems\n"));
return;
}
- acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
}
/*
@@ -1137,6 +1116,15 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
#else
cx->latency_ticks = cx->latency;
#endif
+ /*
+ * On older chipsets, BM_RLD needs to be set
+ * in order for Bus Master activity to wake the
+ * system from C3. Newer chipsets handle DMA
+ * during C3 automatically and BM_RLD is a NOP.
+ * In either case, the proper way to
+ * handle BM_RLD is to set it and leave it set.
+ */
+ acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
return;
}
@@ -1400,25 +1388,6 @@ static int acpi_idle_bm_check(void)
}
/**
- * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
- * @pr: the processor
- * @target: the new target state
- */
-static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
- struct acpi_processor_cx *target)
-{
- if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
- acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
- pr->flags.bm_rld_set = 0;
- }
-
- if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
- acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
- pr->flags.bm_rld_set = 1;
- }
-}
-
-/**
* acpi_idle_do_entry - a helper function that does C2 and C3 type entry
* @cx: cstate data
*
@@ -1473,9 +1442,6 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
return 0;
}
- if (pr->flags.bm_check)
- acpi_idle_update_bm_rld(pr, cx);
-
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
@@ -1527,9 +1493,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
*/
acpi_state_timer_broadcast(pr, cx, 1);
- if (pr->flags.bm_check)
- acpi_idle_update_bm_rld(pr, cx);
-
if (cx->type == ACPI_STATE_C3)
ACPI_FLUSH_CPU_CACHE();
@@ -1621,8 +1584,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
*/
acpi_state_timer_broadcast(pr, cx, 1);
- acpi_idle_update_bm_rld(pr, cx);
-
/*
* disable bus master
* bm_check implies we need ARB_DIS