Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e12f65f7 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

locking, ACPI: Annotate c3_lock as raw 



We cannot preempt this lock on -rt as we are in an
interrupt disabled region and about to go into deep sleep.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2d21a29f

drivers/acpi/processor_idle.c

+5 −5
Original line number Diff line number Diff line
@@ -852,7 +852,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, 
}



static int c3_cpu_count;

static DEFINE_SPINLOCK(c3_lock);

static DEFINE_RAW_SPINLOCK(c3_lock);



/**

 * acpi_idle_enter_bm - enters C3 with proper BM handling
@@ -930,12 +930,12 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, 
	 * without doing anything.

	 */

	if (pr->flags.bm_check && pr->flags.bm_control) {

		spin_lock(&c3_lock);

		raw_spin_lock(&c3_lock);

		c3_cpu_count++;

		/* Disable bus master arbitration when all CPUs are in C3 */

		if (c3_cpu_count == num_online_cpus())

			acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);

		spin_unlock(&c3_lock);

		raw_spin_unlock(&c3_lock);

	} else if (!pr->flags.bm_check) {

		ACPI_FLUSH_CPU_CACHE();

	}
@@ -944,10 +944,10 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, 


	/* Re-enable bus master arbitration */

	if (pr->flags.bm_check && pr->flags.bm_control) {

		spin_lock(&c3_lock);

		raw_spin_lock(&c3_lock);

		acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);

		c3_cpu_count--;

		spin_unlock(&c3_lock);

		raw_spin_unlock(&c3_lock);

	}

	kt2 = ktime_get_real();

	idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));