From: daniel.lezcano@linaro•org (Daniel Lezcano)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 4/9] clocksource/cadence_ttc: Use enable/disable_irq
Date: Thu, 28 Nov 2013 12:55:38 +0100 [thread overview]
Message-ID: <52972F3A.9090103@linaro.org> (raw)
In-Reply-To: <1385514296-26702-5-git-send-email-soren.brinkmann@xilinx.com>
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 <soren.brinkmann@xilinx•com>
> ---
> 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.
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next prev parent reply other threads:[~2013-11-28 11:55 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-27 1:04 [PATCH v2 0/9] arm: zynq: Add support for cpufreq Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 1/9] arm: dt: zynq: Remove 'clock-ranges' from TTC nodes Soren Brinkmann
2013-12-12 8:53 ` Michal Simek
2013-12-12 17:01 ` Sören Brinkmann
2013-12-12 19:07 ` Michal Simek
2013-11-27 1:04 ` [PATCH v2 2/9] arm: dt: zynq: Add 'cpus' node Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 3/9] clocksource/cadence_ttc: Store timer frequency in driver data Soren Brinkmann
2013-12-17 19:21 ` Sören Brinkmann
2013-12-18 14:53 ` Daniel Lezcano
2013-12-18 16:47 ` Sören Brinkmann
2013-12-18 21:58 ` Daniel Lezcano
2013-12-19 18:32 ` Sören Brinkmann
2013-12-19 20:53 ` Daniel Lezcano
2013-12-19 21:23 ` Sören Brinkmann
2013-12-19 21:39 ` Daniel Lezcano
2013-11-27 1:04 ` [PATCH v2 4/9] clocksource/cadence_ttc: Use enable/disable_irq Soren Brinkmann
2013-11-28 11:55 ` Daniel Lezcano [this message]
2013-11-28 14:18 ` Thomas Gleixner
2013-11-28 18:36 ` Sören Brinkmann
2013-11-28 19:07 ` Thomas Gleixner
2013-12-06 22:47 ` Sören Brinkmann
2013-12-07 10:56 ` Thomas Gleixner
2013-12-10 0:34 ` [PATCH 0/2] clockevents Soren Brinkmann
2013-12-10 0:34 ` [PATCH 1/2] time: Serialize calls to 'clockevents_update_freq' in the timing core Soren Brinkmann
2013-12-11 14:32 ` Daniel Lezcano
2013-12-11 20:09 ` Sören Brinkmann
2013-12-12 12:07 ` Daniel Lezcano
2013-12-10 0:34 ` [PATCH 2/2] time: clockevents: Adjust timer interval when frequency changes Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 5/9] clocksource/cadence_ttc: Adjust interval in clock notifier Soren Brinkmann
2013-12-12 12:15 ` Daniel Lezcano
2013-12-12 18:44 ` Sören Brinkmann
2013-11-27 1:04 ` [PATCH v2 6/9] clocksource/cadence_ttc: Overhaul clocksource frequency adjustment Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 7/9] clocksource/cadence_ttc: Use only one counter Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 8/9] arm: zynq: Don't use arm_global_timer with cpufreq Soren Brinkmann
2013-11-27 1:04 ` [PATCH v2 9/9] arm: zynq: Add support for cpufreq Soren Brinkmann
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