From: Len Brown <len.brown@xxxxxxxxx>
PM1a_STS and PM1b_STS are twins that get OR'd together
on reads, and all writes are repeated to both.
The fields in PM1x_STS are single bits only,
there are no multi-bit fields.
So it is not necessary to lock PM1x_STS reads against
writes because it is impossible to read an intermediate
value of a single bit. It will either be 0 or 1,
even if a write is in progress during the read.
Reads are asynchronous to writes no matter if a lock
is used or not.
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/acpi/processor_idle.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 66a9d81..ae00108 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -447,7 +447,7 @@ static void acpi_processor_idle(void)
pr->power.bm_activity <<= diff;
- acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
+ acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
if (bm_status) {
pr->power.bm_activity |= 0x1;
acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
@@ -1383,7 +1383,7 @@ static int acpi_idle_bm_check(void)
{
u32 bm_status = 0;
- acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
+ acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
if (bm_status)
acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
/*
--
1.6.1.2.319.gbd9e
--
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