Commit 259c95af authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

arm, OMAP2: Use WFI for omap2_pm_idle() 



arch_cpu_idle() is a very simple idle interface and exposes only a
single idle state and is expected to not require RCU and not do any
tracing/instrumentation.

As such, omap2_pm_idle() is not a valid implementation. Replace it
with a simple (shallow) omap2_do_wfi() call.

Omap2 doesn't have a cpuidle driver; but adding one would be the
recourse to (re)gain the other idle states.

Suggested-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Tested-by: default avatarTony Lindgren <tony@atomide.com>
Tested-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.721697850@infradead.org
parent a282e5ef

arch/arm/mach-omap2/pm24xx.c

+2 −49
Original line number Diff line number Diff line
@@ -116,50 +116,12 @@ static int omap2_enter_full_retention(void) 


static int sti_console_enabled;



static int omap2_allow_mpu_retention(void)

{

	if (!omap2xxx_cm_mpu_retention_allowed())

		return 0;

	if (sti_console_enabled)

		return 0;



	return 1;

}



static void omap2_enter_mpu_retention(void)

static void omap2_do_wfi(void)

{

	const int zero = 0;



	/* The peripherals seem not to be able to wake up the MPU when

	 * it is in retention mode. */

	if (omap2_allow_mpu_retention()) {

		/* REVISIT: These write to reserved bits? */

		omap_prm_clear_mod_irqs(CORE_MOD, PM_WKST1, ~0);

		omap_prm_clear_mod_irqs(CORE_MOD, OMAP24XX_PM_WKST2, ~0);

		omap_prm_clear_mod_irqs(WKUP_MOD, PM_WKST, ~0);



		/* Try to enter MPU retention */

		pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);



	} else {

		/* Block MPU retention */

		pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);

	}



	/* WFI */

	asm("mcr p15, 0, %0, c7, c0, 4" : : "r" (zero) : "memory", "cc");



	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);

}



static int omap2_can_sleep(void)

{

	if (omap2xxx_cm_fclks_active())

		return 0;

	if (__clk_is_enabled(osc_ck))

		return 0;



	return 1;

}



static void omap2_pm_idle(void)
@@ -169,16 +131,7 @@ static void omap2_pm_idle(void) 
	if (omap_irq_pending())

		return;



	error = cpu_cluster_pm_enter();

	if (error || !omap2_can_sleep()) {

		omap2_enter_mpu_retention();

		goto out_cpu_cluster_pm;

	}



	omap2_enter_full_retention();



out_cpu_cluster_pm:

	cpu_cluster_pm_exit();

	omap2_do_wfi();

}



static void __init prcm_setup_regs(void)