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Commit 66f49121 authored by Aurelien Jarno's avatar Aurelien Jarno Committed by Paul Mundt
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clocksource: sh_tmu: compute mult and shift before registration 



Since commit 98962465 ("nohz: Prevent
clocksource wrapping during idle"), the CPU of an R2D board never goes
to idle. This commit assumes that mult and shift are assigned before
the clocksource is registered. As a consequence the safe maximum sleep
time is negative and the CPU never goes into idle.

This patch fixes the problem by moving mult and shift initialization
from sh_tmu_clocksource_enable() to sh_tmu_register_clocksource().

Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
Cc: stable@kernel.org
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 019e2574

drivers/clocksource/sh_tmu.c

+11 −9
Original line number Diff line number Diff line
@@ -199,16 +199,8 @@ static cycle_t sh_tmu_clocksource_read(struct clocksource *cs) 
static int sh_tmu_clocksource_enable(struct clocksource *cs)

{

	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);

	int ret;



	ret = sh_tmu_enable(p);

	if (ret)

		return ret;



	/* TODO: calculate good shift from rate and counter bit width */

	cs->shift = 10;

	cs->mult = clocksource_hz2mult(p->rate, cs->shift);

	return 0;

	return sh_tmu_enable(p);

}



static void sh_tmu_clocksource_disable(struct clocksource *cs)
@@ -228,6 +220,16 @@ static int sh_tmu_register_clocksource(struct sh_tmu_priv *p, 
	cs->disable = sh_tmu_clocksource_disable;

	cs->mask = CLOCKSOURCE_MASK(32);

	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;



	/* clk_get_rate() needs an enabled clock */

	clk_enable(p->clk);

	/* channel will be configured at parent clock / 4 */

	p->rate = clk_get_rate(p->clk) / 4;

	clk_disable(p->clk);

	/* TODO: calculate good shift from rate and counter bit width */

	cs->shift = 10;

	cs->mult = clocksource_hz2mult(p->rate, cs->shift);



	dev_info(&p->pdev->dev, "used as clock source\n");

	clocksource_register(cs);

	return 0;