Messages in this thread | | | Date | Thu, 5 Jun 2014 12:51:46 -0700 | Subject | Re: [PATCH V5 2/2] cpufreq: Tegra: implement intermediate frequency callbacks | From | Doug Anderson <> |
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Viresh,
On Mon, Jun 2, 2014 at 10:19 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote: > Tegra had always been switching to intermediate frequency (pll_p_clk) since > ever. CPUFreq core has better support for handling notifications for these > frequencies and so we can adapt Tegra's driver to it. > > Also do a WARN() if clk_set_parent() fails while moving back to pll_x as we > should have atleast restored to earlier frequency on error. > > Tested-by: Stephen Warren <swarren@nvidia.com> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/cpufreq/tegra-cpufreq.c | 97 ++++++++++++++++++++++++++--------------- > 1 file changed, 62 insertions(+), 35 deletions(-) > > diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c > index 6e774c6..a5fbc0a 100644 > --- a/drivers/cpufreq/tegra-cpufreq.c > +++ b/drivers/cpufreq/tegra-cpufreq.c > @@ -45,46 +45,51 @@ static struct clk *cpu_clk; > static struct clk *pll_x_clk; > static struct clk *pll_p_clk; > static struct clk *emc_clk; > +static bool pll_x_prepared; > > -static int tegra_cpu_clk_set_rate(unsigned long rate) > +static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy, > + unsigned int index) > +{ > + unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000; > + > + /* > + * Don't switch to intermediate freq if: > + * - we are already at it, i.e. policy->cur == ifreq > + * - index corresponds to ifreq > + */ > + if ((freq_table[index].frequency == ifreq) || (policy->cur == ifreq)) > + return 0; > + > + return ifreq; > +} > + > +static int tegra_target_intermediate(struct cpufreq_policy *policy, > + unsigned int index) > { > int ret; > > /* > * Take an extra reference to the main pll so it doesn't turn > - * off when we move the cpu off of it > + * off when we move the cpu off of it as enabling it again while we > + * switch to it from tegra_target() would take additional time. Though > + * when target-freq is intermediate freq, we don't need to take this > + * reference.
The "Though when target-freq is intermediate freq, we don't need to take this reference." makes me think that this function is actually called when target-freq is intermediate freq. I don't think it is, right?
I don't think that's a huge deal, though and code wise this looks good to me.
Reviewed-by: Doug Anderson <dianders@chromium.org>
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