lkml.org 
[lkml]   [2016]   [Jun]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] PM / OPP: 'UNKNOWN' status of opp-table->shared
On 16-06-16, 15:55, Alexandre Courbot wrote:
> On 06/16/2016 03:33 PM, Viresh Kumar wrote:
> >dev_pm_opp_get_sharing_cpus() returns 0 even in the case where the OPP
> >core doesn't know if the table is shared or not. It is working for most
> >of the platforms, as the OPP table was never created and we returned
> >-ENODEV then.
> >
> >But in case of one of the platforms (Jetson TK1) at least, the situation
> >is a bit different. The OPP table is created (somehow) before
> >dev_pm_opp_get_sharing_cpus() is called and so we returned 0. The caller
> >of this routine treated that as 'CPUs don't share OPPs' and that had bad
> >consequences on performance.
> >
> >Fix this by converting 'shared_opp' to an integer and have an extra
> >value when its state in undefined. dev_pm_opp_get_sharing_cpus() returns
> >-EINVAL now in that case, so that the caller can handle it accordingly
> >(cpufreq-dt considers that as 'all CPUs share the table').
> >
> >Fixes: 6f707daa3833 ("PM / OPP: Add dev_pm_opp_get_sharing_cpus()")
> >Reported-by: Alexandre Courbot <acourbot@nvidia.com>
> >Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> >---
> >Hi Alexandre,
> >
> >This is untested, can you please confirm if this fixes it for you?
>
> Yep, with this cpufreq_init() takes the fallback path and cpufreq behaves as
> expected thereafter.
>
> Thanks for reacting so quickly! Can this go into 4.7 fixes?

This will :)

> Tested-by: Alexandre Courbot <acourbot@nvidia.com>

Thanks.

--
viresh

\
 
 \ /
  Last update: 2016-06-16 09:41    [W:0.109 / U:0.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site