On 11/27/2013 02:04 AM, Soren Brinkmann wrote:
To ensure that the timer interrupt is properly enabled/disabled across
the whole CPU cluster use enable/disable_irq() instead of
local_irq_disable().

Signed-off-by: Soren Brinkmann <[email protected]>
---
  drivers/clocksource/cadence_ttc_timer.c | 6 ++----
  1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/cadence_ttc_timer.c 
b/drivers/clocksource/cadence_ttc_timer.c
index a92350b55d32..246d018d1e63 100644
--- a/drivers/clocksource/cadence_ttc_timer.c
+++ b/drivers/clocksource/cadence_ttc_timer.c
@@ -322,18 +322,16 @@ static int ttc_rate_change_clockevent_cb(struct 
notifier_block *nb,
        switch (event) {
        case POST_RATE_CHANGE:
        {
-               unsigned long flags;
-
                /*
                 * clockevents_update_freq should be called with IRQ disabled on
                 * the CPU the timer provides events for. The timer we use is
                 * common to both CPUs, not sure if we need to run on both
                 * cores.
                 */
-               local_irq_save(flags);
+               disable_irq(ttcce->ce.irq);
                clockevents_update_freq(&ttcce->ce,
                                ndata->new_rate / PRESCALE);
-               local_irq_restore(flags);
+               enable_irq(ttcce->ce.irq);

                /* update cached frequency */
                ttc->freq = ndata->new_rate;


I am worried about the 'disable_irq' function calling 'synchronize_irq'. Isn't possible to deadlock with the ondemand cpufreq governor ? I added Viresh in Cc, he knows better than me the code path.

--
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to