Re: [PATCH 2/3] clk: tegra: Warn if an enabled PLL is in IDDQ

[Thierry Reding <thierry.reding@gmail.com>]

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On Mon, Jun 17, 2019 at 11:39:48AM +0100, Jon Hunter wrote:
> 
> On 13/06/2019 17:12, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > A PLL in IDDQ doesn't work, whether it's enabled or not. This is not a
> > configuration that makes sense, so warn about it.
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/clk/tegra/clk-tegra210.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> > index 4904ac4a75db..793c7acaf4e2 100644
> > --- a/drivers/clk/tegra/clk-tegra210.c
> > +++ b/drivers/clk/tegra/clk-tegra210.c
> > @@ -1003,8 +1003,12 @@ static void tegra210_pllre_set_defaults(struct tegra_clk_pll *pllre)
> >  		_pll_misc_chk_default(clk_base, pllre->params, 0, val,
> >  				~mask & PLLRE_MISC0_WRITE_MASK);
> >  
> > -		/* Enable lock detect */
> > +		/* The PLL doesn't work if it's in IDDQ. */
> >  		val = readl_relaxed(clk_base + pllre->params->ext_misc_reg[0]);
> > +		if (val & PLLRE_MISC0_IDDQ)
> > +			pr_warn("unexpected IDDQ bit set for enabled clock\n");
> > +
> > +		/* Enable lock detect */
> >  		val &= ~mask;
> >  		val |= PLLRE_MISC0_DEFAULT_VALUE & mask;
> >  		writel_relaxed(val, clk_base + pllre->params->ext_misc_reg[0]);
> 
> Looks like there are a few other instances of this that could be fixed
> as well.

Yeah. This is the only one that's showing up in logs, so I was
concentrating on this one. I'll make another pass over the driver and
clean up the rest of them in a separate patch.

Thierry

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