diff options
| author | Aurelien Jarno <aurelien@aurel32.net> | 2010-05-31 21:45:48 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-07-05 11:22:42 -0700 |
| commit | a214985570a6290d46800fe235f49b2989bfd784 (patch) | |
| tree | d17e54f6a4a279c24277d810e50699c0dbd1ec08 /drivers | |
| parent | fe7f657830d40cc5a21952d7131f0bfdf4aff79d (diff) | |
clocksource: sh_tmu: compute mult and shift before registration
commit 66f49121ffa41a19c59965b31b046d8368fec3c7 upstream.
Since commit 98962465ed9e6ea99c38e0af63fe1dcb5a79dc25 ("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: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/clocksource/sh_tmu.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c index fc9ff1e5b77..7a241608848 100644 --- a/drivers/clocksource/sh_tmu.c +++ b/drivers/clocksource/sh_tmu.c @@ -200,16 +200,8 @@ 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) @@ -229,6 +221,16 @@ 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); + pr_info("sh_tmu: %s used as clock source\n", cs->name); clocksource_register(cs); return 0; |