From: Len Brown Date: Wed, 28 Jan 2009 17:47:15 +0000 (-0500) Subject: ACPI: remove locking from PM1x_STS register reads X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=a2b7b01c072435b7832ab392167545a1b38cabc3;p=linux-2.6-omap-h63xx.git 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 --- diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 66a9d814556..ae0010821ce 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); /*