linux-kernel - Re: [PATCH V1] PM: In kernel power management domain

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Date:   Wed, 06 Dec 2017 15:18:15 +0100
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        Vikas Bansal <vikas.bansal@...sung.com>
Cc:     "len.brown@...el.com" <len.brown@...el.com>,
        "pavel@....cz" <pavel@....cz>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V1] PM: In kernel power management domain_pm created for async schedules

On Wednesday, December 6, 2017 3:12:38 PM CET gregkh@...uxfoundation.org wrote:
> On Wed, Dec 06, 2017 at 12:07:14PM +0000, Vikas Bansal wrote:
> > Description:
> 
> Why is this here?
> 
> > 
> > If there is a driver in system which starts creating async schedules
> > just after resume (Same as our case, in which we faced issue).
> > Then async_synchronize_full API in PM cores starts waiting for completion
> > of async schedules created by that driver (Even though those are in a domain).
> > Because of this kernel resume time is increased (We faces the same issue)
> > and whole system is delayed.
> > This problem can be solved by creating a domain for
> > async schedules in PM core (As we solved in our case).
> > Below patch is for solving this problem.
> 
> Very odd formatting.
> 
> > 
> > Changelog:
> > 1. Created Async domain domain_pm.
> > 2. Converted async_schedule to async_schedule_domain.
> > 3. Converted async_synchronize_full to async_synchronize_full_domain
> 
> I'm confused.  Have you read kernel patch submissions?  Look at how they
> are formatted.  The documentation in the kernel tree should help you out
> a lot here.
> 
> Also, this is not v1, it has changed from the previous version.  Always
> describe, in the correct way, the changes from previous submissions.
> 
> 
> > 
> > 
> > 
> > Signed-off-by: Vikas Bansal <vikas.bansal@...sung.com>
> > Signed-off-by: Anuj Gupta <anuj01.gupta@...sung.com>
> > ---
> >  drivers/base/power/main.c |   27 +++++++++++++++------------
> >  1 file changed, 15 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> > index db2f044..042b034 100644
> > --- a/drivers/base/power/main.c
> > +++ b/drivers/base/power/main.c
> > @@ -39,6 +39,7 @@
> >  #include "power.h"
> >  
> >  typedef int (*pm_callback_t)(struct device *);
> > +static ASYNC_DOMAIN(domain_pm);
> >  
> >  /*
> >   * The entries in the dpm_list list are in a depth first order, simply
> > @@ -615,7 +616,8 @@ void dpm_noirq_resume_devices(pm_message_t state)
> >  		reinit_completion(&dev->power.completion);
> >  		if (is_async(dev)) {
> >  			get_device(dev);
> > -			async_schedule(async_resume_noirq, dev);
> > +			async_schedule_domain(async_resume_noirq, dev, 
> 
> Always run your patches through scripts/checkpatch.pl so you do you not
> get grumpy maintainers telling you to use scripts/checkpatch.pl
> 
> Stop.  Take some time.  Redo the patch in another day or so, and then
> resend it later, _AFTER_ you have addressed the issues.  Don't rush,
> there is no race here.

Also it is not clear to me if this fixes a mainline kernel issue,
because the changelog mentions a driver doing something odd, but it
doesn't say which one it is and whether or not it is in the tree.

Thanks,
Rafael