On Wed, Jun 22, 2011 at 05:07:44PM +0900, Kukjin Kim wrote:
> From: Todd Poynor <toddpoynor@xxxxxxxxxx>
>
> Voltage scaling accesses the MAX8998 regulators over bit-banged I2C
> with lots of udelays. In the case of decreasing CPU speed, the
> number of loops per us for udelay needs to be adjusted prior to
> decreasing voltage to avoid delaying for up to 10X too long.
This changelog is very specific to a particular board but actually it's
not at all board specific - we should watch out for this with other
cpufreq drivers as I bet there's more with the same issue. The S3C64xx
driver is affected for example, I'll send a patch shortly.
>
> Signed-off-by: Todd Poynor <toddpoynor@xxxxxxxxxx>
> Signed-off-by: Jonghwan Choi <jhbird.choi@xxxxxxxxxxx>
> Signed-off-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx>
> ---
> drivers/cpufreq/s5pv210-cpufreq.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
> index e9b9b7f..78c88a0 100644
> --- a/drivers/cpufreq/s5pv210-cpufreq.c
> +++ b/drivers/cpufreq/s5pv210-cpufreq.c
> @@ -471,6 +471,8 @@ static int s5pv210_target(struct cpufreq_policy *policy,
> }
> }
>
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> +
> if (freqs.new < freqs.old) {
> /* Voltage down: will be implemented */
> if (!IS_ERR(arm_regulator) &&
> @@ -483,7 +485,6 @@ static int s5pv210_target(struct cpufreq_policy *policy,
> }
> }
>
> - cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
>
> printk(KERN_DEBUG "Perf changed[L%d]\n", index);
>
> --
> 1.7.1
>
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