Hi Reshma, 

   I'm OK with the change. That's the missing part about init process.

Reviewed-by Liang Ma <liang.j...@intel.com>

Regards
Liang

On 29 Jul 14:58, Reshma Pattan wrote:
> 1)
> During power initialization the pstate cpufreq api is
> not setting the initial curr_idx of pstate_power_info
> to corresponding current frequency index.
> 
> Without this the idx is always 0, which is causing the
> below check to pass and returns without setting the initial
> min/max frequency to system max frequency and this leads to
> incorrect frequency settings when power_pstate_cpufreq_set_freq()
> is called in the apps.
> 
> set_freq_internal(struct pstate_power_info *pi, uint32_t idx)
> {
> ...
> 
>  /* Check if it is the same as current */
>         if (idx == pi->curr_idx)
>                 return 0;
> ...
> }
> 
> scenario 1:
> If system has starting scaling min/max: 1000/1000, and want to
> set this to 2200/2200, the max frequency gets updated but not min.
> 
> scenario 2:
> If system has starting scaling min/max: 2200/1000, and want to set
> to 2200/2200, the max, min frequency was not updated. Since no change
> in max that should be ok, but min was also ignored, which will be fixed
> now with the new changes.
> 
> Fixes: e6c6dc0f ("power: add p-state driver compatibility")
> Cc: sta...@dpdk.org
> CC: liang.j...@intel.com
> Signed-off-by: Reshma Pattan <reshma.pat...@intel.com>
> ---
>  lib/librte_power/power_pstate_cpufreq.c | 59 
> +++++++++++++++++++++++++++++++++
>  1 file changed, 59 insertions(+)
> 
> diff --git a/lib/librte_power/power_pstate_cpufreq.c 
> b/lib/librte_power/power_pstate_cpufreq.c
> index 2526441..262f024 100644
> --- a/lib/librte_power/power_pstate_cpufreq.c
> +++ b/lib/librte_power/power_pstate_cpufreq.c
> @@ -52,6 +52,9 @@
>               } \
>  } while (0)
>  
> +/* macros used for rounding frequency to nearest 100000 */
> +#define FREQ_ROUNDING_DELTA 50000
> +#define ROUND_FREQ_TO_N_100000 100000
>  
>  #define POWER_CONVERT_TO_DECIMAL 10
>  #define BUS_FREQ     100000
> @@ -532,6 +535,57 @@ struct pstate_power_info {
>       return ret;
>  }
>  
> +static int
> +power_get_cur_idx(struct pstate_power_info *pi)
> +{
> +     FILE *f_cur;
> +     int ret = -1;
> +     char *p_cur;
> +     char buf_cur[BUFSIZ];
> +     char fullpath_cur[PATH_MAX];
> +     char *s_cur;
> +     uint32_t sys_cur_freq = 0;
> +     unsigned int i;
> +
> +     snprintf(fullpath_cur, sizeof(fullpath_cur),
> +                     POWER_SYSFILE_CUR_FREQ,
> +                     pi->lcore_id);
> +     f_cur = fopen(fullpath_cur, "r");
> +     FOPEN_OR_ERR_RET(f_cur, ret);
> +
> +     /* initialize the cur_idx to matching current frequency freq index */
> +     s_cur = fgets(buf_cur, sizeof(buf_cur), f_cur);
> +     FOPS_OR_NULL_GOTO(s_cur, fail);
> +
> +     p_cur = strchr(buf_cur, '\n');
> +     if (p_cur != NULL)
> +             *p_cur = 0;
> +     sys_cur_freq = strtoul(buf_cur, &p_cur, POWER_CONVERT_TO_DECIMAL);
> +
> +     /* convert the frequency to nearest 100000 value
> +      * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
> +      * Ex: if sys_cur_freq=800030 then freq_conv=800000
> +      * Ex: if sys_cur_freq=800030 then freq_conv=800000
> +      */
> +     unsigned int freq_conv = 0;
> +     freq_conv = (sys_cur_freq + FREQ_ROUNDING_DELTA)
> +                             / ROUND_FREQ_TO_N_100000;
> +     freq_conv = freq_conv * ROUND_FREQ_TO_N_100000;
> +
> +     for (i = 0; i < pi->nb_freqs; i++) {
> +             if (freq_conv == pi->freqs[i]) {
> +                     pi->curr_idx = i;
> +                     break;
> +             }
> +     }
> +
> +     fclose(f_cur);
> +     return 0;
> +fail:
> +     fclose(f_cur);
> +     return ret;
> +}
> +
>  int
>  power_pstate_cpufreq_check_supported(void)
>  {
> @@ -578,6 +632,11 @@ struct pstate_power_info {
>               goto fail;
>       }
>  
> +     if (power_get_cur_idx(pi) < 0) {
> +             RTE_LOG(ERR, POWER, "Cannot get current frequency "
> +                             "index of lcore %u\n", lcore_id);
> +             goto fail;
> +     }
>  
>       /* Set freq to max by default */
>       if (power_pstate_cpufreq_freq_max(lcore_id) < 0) {
> -- 
> 1.8.3.1
> 

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