RE: [PATCH v4] scsi: ufs: Fix imprecise load calculation in devfreq window

[Stanley Chu]

Hi Avri,

Thanks for the review.

On Thu, 2020-06-11 at 08:03 +0000, Avri Altman wrote:
> > 
> > Fixes: a3cd5ec55f6c ("scsi: ufs: add load based scaling of UFS gear")
> > Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
> 
> Just a small nit.
> 
> > -       stat->total_time = jiffies_to_usecs((long)jiffies -
> > -                               (long)scaling->window_start_t);
> > +       stat->total_time = ktime_to_us(curr_t) - scaling->window_start_t;
> ktime_sub ?

scaling->window_start_t is already in "us" thus ktime_sub() is not
suitable here.

Another way is changing scaling->window_start_t as type "ktime_t". This
is worth to do because of a little performance gain.

I will change it in next version.

Thanks,
Stanley Chu