Commit f3a9022f authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: sr.bl toggling around idle sleep. 



As pointed out by Saito-san, without the sr.bl manipulation we can
occasionally hit delays in the idle loop due to interrupt handling, so
ensure that interrupts are blocked before going to sleep.

At the same time, we throw in TIF_POLLING_NRFLAG for the !hlt_counter
case (primarily used by the ST-40 parts).

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 69d87daa

arch/sh/kernel/process.c

+27 −6
Original line number Diff line number Diff line
@@ -26,8 +26,6 @@ 
static int hlt_counter;

int ubc_usercnt = 0;



#define HARD_IDLE_TIMEOUT (HZ / 3)



void (*pm_idle)(void);

void (*pm_power_off)(void);

EXPORT_SYMBOL(pm_power_off);
@@ -44,16 +42,39 @@ void enable_hlt(void) 
}

EXPORT_SYMBOL(enable_hlt);



static int __init nohlt_setup(char *__unused)

{

	hlt_counter = 1;

	return 1;

}

__setup("nohlt", nohlt_setup);



static int __init hlt_setup(char *__unused)

{

	hlt_counter = 0;

	return 1;

}

__setup("hlt", hlt_setup);



void default_idle(void)

{

	if (!hlt_counter)

	if (!hlt_counter) {

		clear_thread_flag(TIF_POLLING_NRFLAG);

		smp_mb__after_clear_bit();

		set_bl_bit();

		while (!need_resched())

			cpu_sleep();

	else

		clear_bl_bit();

		set_thread_flag(TIF_POLLING_NRFLAG);

	} else

		while (!need_resched())

			cpu_relax();

}



void cpu_idle(void)

{

	set_thread_flag(TIF_POLLING_NRFLAG);



	/* endless idle loop with no priority at all */

	while (1) {

		void (*idle)(void) = pm_idle;

CRA Git | Maintained and supported by SUSTech CRA and CCSE