linux-kernel - Re: [PATCH v3 3/3] arm: omap_hwmod disable ick autoidling when a hwmod requires that

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Message-ID: <20190118194536.GY5544@atomide.com>
Date:   Fri, 18 Jan 2019 11:45:36 -0800
From:   Tony Lindgren <tony@...mide.com>
To:     Andreas Kemnade <andreas@...nade.info>
Cc:     t-kristo@...com, mturquette@...libre.com, sboyd@...nel.org,
        linux-omap@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, bcousson@...libre.com,
        paul@...an.com, letux-kernel@...nphoenux.org
Subject: Re: [PATCH v3 3/3] arm: omap_hwmod disable ick autoidling when a
 hwmod requires that

* Andreas Kemnade <andreas@...nade.info> [190118 19:39]:
> Hi,
> 
> On Fri, 18 Jan 2019 10:36:30 -0800
> Tony Lindgren <tony@...mide.com> wrote:
> 
> [...]
> > til the next workaround.
> > 
> > > That flags also causes the iclk being enabled/disabled
> > > manually.  
> > 
> > Yes but SWSUP_IDLE for the interface clock to me currently
> > just means:
> > 
> > "manually enable and disable ocp interface clock"
> > 
> well, if we want to manually disable it and not automatically,
> we have to disable autoidle or it will be automatically disabled.
> 
> Disabling it manually when it is already auto-disabled (by autoidle) is
> just practically a no-op towards the clock.

OK I buy that :) It should be probably added to the patch
description to make it clear what it changes.

Tero, any comments on this change?

> > and with your changes it becomes:
> > 
> > "manually enable and disable ocp interface clock and block
> >  autoidle while in use".
> > 
> > So aren't we now changing the way things behave in general
> > for SWSUP_IDLE?
> > 
> Yes, we are, so proper testing is needed. But If I read those comments
> it was always intended this way but not fully implemented because it
> appeared to be more work like needing a usecounter (which my patchset
> also adds) for that autoidle flag.

OK yeah the use count seems necessary. I'll test here
with my PM use cases.

Regards,

Tony