Re: [PATCH] cpufreq: exynos5440: Protect opp search calls with rcu lock

From: Rafael J. Wysocki
Date: Sun Apr 21 2013 - 19:24:20 EST


On Monday, April 15, 2013 11:54:47 AM Amit Daniel Kachhap wrote:
> As per the OPP library documentation(Documentation/power/opp.txt) all
> opp find/get calls should be protected by rcu locks.
>
> Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
> ---
>
> This patch is created against linux-next tree and is suggested by
> Nishanth Menon. (https://lkml.org/lkml/2013/4/12/119)

Applied.

Thanks,
Rafael


> drivers/cpufreq/exynos5440-cpufreq.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
> index ead7ed4..0c74018 100644
> --- a/drivers/cpufreq/exynos5440-cpufreq.c
> +++ b/drivers/cpufreq/exynos5440-cpufreq.c
> @@ -120,11 +120,13 @@ static int init_div_table(void)
> int i = 0;
> struct opp *opp;
>
> + rcu_read_lock();
> for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
>
> opp = opp_find_freq_exact(dvfs_info->dev,
> freq_tbl[i].frequency * 1000, true);
> if (IS_ERR(opp)) {
> + rcu_read_unlock();
> dev_err(dvfs_info->dev,
> "failed to find valid OPP for %u KHZ\n",
> freq_tbl[i].frequency);
> @@ -159,6 +161,7 @@ static int init_div_table(void)
> __raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
> }
>
> + rcu_read_unlock();
> return 0;
> }
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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