Subject: Re: [PATCH] cpufreq: ppc-corenet-cpu-freq: do_div use quotient

From: Tim Gardner <[email-masked]>
Date: Fri, 06 Jun 2014 08:03:40 -0600

On 06/04/2014 02:32 PM, Ed Swarthout wrote:
> 6712d2931933ada259b82f06c03a855b19937074 (cpufreq:
> ppc-corenet-cpufreq: Fix __udivdi3 modpost error) used the remainder
> from do_div instead of the quotient. Fix that and add one to ensure
> minimum is met.
> 
> Signed-off-by: Ed Swarthout <[email-masked]>
> ---
>  drivers/cpufreq/ppc-corenet-cpufreq.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
> index 0af618a..3607070 100644
> --- a/drivers/cpufreq/ppc-corenet-cpufreq.c
> +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
> @@ -138,7 +138,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
>  	struct cpufreq_frequency_table *table;
>  	struct cpu_data *data;
>  	unsigned int cpu = policy->cpu;
> -	u64 transition_latency_hz;
> +	u64 u64temp;
>  
>  	np = of_get_cpu_node(cpu, NULL);
>  	if (!np)
> @@ -206,9 +206,10 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
>  	for_each_cpu(i, per_cpu(cpu_mask, cpu))
>  		per_cpu(cpu_data, i) = data;
>  
> -	transition_latency_hz = 12ULL * NSEC_PER_SEC;
> -	policy->cpuinfo.transition_latency =
> -		do_div(transition_latency_hz, fsl_get_sys_freq());
> +	/* Minimum transition latency is 12 platform clocks */
> +	u64temp = 12ULL * NSEC_PER_SEC;
> +	do_div(u64temp, fsl_get_sys_freq());
> +	policy->cpuinfo.transition_latency = u64temp + 1;
>  
>  	of_node_put(np);
>  
> 

Whoops, what was I thinking ? You should also add "Cc:
[email-masked] # 3.15+" since this patch will likely miss 3.15
final.

Acked-by: Tim Gardner <[email-masked]>

-- 
Tim Gardner [email-masked]