diff options
| author | Len Brown <len.brown@intel.com> | 2009-01-28 12:47:15 -0500 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-01-28 13:59:56 -0500 |
| commit | a2b7b01c072435b7832ab392167545a1b38cabc3 (patch) | |
| tree | 6a8aeb8723c71bc819d9576ebbb6bc2110513a40 | |
| parent | 152a649b647a8ef47bb74ff9e11850fa6001bedc (diff) | |
| download | op-kernel-dev-a2b7b01c072435b7832ab392167545a1b38cabc3.zip op-kernel-dev-a2b7b01c072435b7832ab392167545a1b38cabc3.tar.gz | |
ACPI: remove locking from PM1x_STS register reads
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@intel.com>
| -rw-r--r-- | 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); /* |
