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

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Message-ID: <20190118204204.44db353f@aktux>
Date:   Fri, 18 Jan 2019 20:42:04 +0100
From:   Andreas Kemnade <andreas@...nade.info>
To:     Tony Lindgren <tony@...mide.com>
Cc:     Discussions about the Letux Kernel <letux-kernel@...nphoenux.org>,
        paul@...an.com, sboyd@...nel.org, mturquette@...libre.com,
        linux-kernel@...r.kernel.org, t-kristo@...com,
        bcousson@...libre.com, linux-omap@...r.kernel.org,
        linux-clk@...r.kernel.org
Subject: Re: [Letux-kernel] [PATCH v3 3/3] arm: omap_hwmod disable ick
 autoidling when a hwmod requires that

On Fri, 18 Jan 2019 20:38:47 +0100
Andreas Kemnade <andreas@...nade.info> wrote:

> 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.
> 
> > 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.
> 
and there are quite few hwmods marked by this flag. 
And then there are those clocks marked by this flags (on am33xx) which
do not have that autoidle feature at all, so the risk is not too high.

Regards,
Andreas

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