Re: [PATCH 2/2] opp: quiet down WARN when no valid OPPs remain

From: Viresh Kumar
Date: Tue Jan 07 2020 - 06:31:01 EST

On 07-01-20, 10:58, MichaÅ MirosÅaw wrote:
> On Tue, Jan 07, 2020 at 12:11:29PM +0530, Viresh Kumar wrote:
> > On 03-01-20, 20:36, MichaÅ MirosÅaw wrote:
> > > Per CPU screenful of backtraces is not really that useful. Replace
> > > WARN with a diagnostic discriminating common causes of empty OPP table.
> > But why should a platform have an OPP table in DT where none of them works for
> > it ? I added the warn intentionally here just for that case.
> Hmm. I guess we can make it WARN_ON_ONCE instead of removing it

I am not sure this will get triggered more than once normally anyway, isn't it ?

> , but I
> don't think the backtrace is ever useful in this case.

Hmm, I am less concerned about backtraces than highlighting problem in a serious
way. The simple print messages are missed many times by people and probably
that's why I used a WARN instead.

> Empty table can
> be because eg. you run old DT on newer hardware version.

Hmm, but then a big warning isn't that bad as we need to highlight the issue to
everyone as cpufreq won't be working. isn't it ?

> This is why
> it's still communicated via dev_err().