Santosh Shilimkar <santosh.shilimkar@xxxxxx> writes: > From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > > Adjust _both_ the per-cpu loops_per_jiffy and global lpj. Calibrate them > with with reference to the initial values to avoid a progressively > bigger and bigger error in the value over time. > > While at this, re-use the notifiers for UP/SMP since on > UP machine or UP_ON_SMP policy->cpus mask would contain only > the boot CPU. > > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > [santosh.shilimkar@xxxxxx: re-based against omap cpufreq > upstream branch and fixed notifiers] > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > Cc: Kevin Hilman <khilman@xxxxxx> Thanks, applied to pm-wip/cpufreq branch. Kevin > --- > Patch is outcome of below discussion. > http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg51559.html > > arch/arm/mach-omap2/omap2plus-cpufreq.c | 50 ++++++++++++++++-------------- > 1 files changed, 27 insertions(+), 23 deletions(-) > > diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach-omap2/omap2plus-cpufreq.c > index 1f3b2e1..de82e87 100644 > --- a/arch/arm/mach-omap2/omap2plus-cpufreq.c > +++ b/arch/arm/mach-omap2/omap2plus-cpufreq.c > @@ -38,6 +38,16 @@ > > #include <mach/hardware.h> > > +#ifdef CONFIG_SMP > +struct lpj_info { > + unsigned long ref; > + unsigned int freq; > +}; > + > +static DEFINE_PER_CPU(struct lpj_info, lpj_ref); > +static struct lpj_info global_lpj_ref; > +#endif > + > static struct cpufreq_frequency_table *freq_table; > static atomic_t freq_table_users = ATOMIC_INIT(0); > static struct clk *mpu_clk; > @@ -96,37 +106,18 @@ static int omap_target(struct cpufreq_policy *policy, > if (freqs.old == freqs.new && policy->cur == freqs.new) > return ret; > > - if (!is_smp()) { > - cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); > - goto set_freq; > - } > - > /* notifiers */ > for_each_cpu(i, policy->cpus) { > freqs.cpu = i; > cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); > } > > -set_freq: > #ifdef CONFIG_CPU_FREQ_DEBUG > pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new); > #endif > > ret = clk_set_rate(mpu_clk, freqs.new * 1000); > - > - /* > - * Generic CPUFREQ driver jiffy update is under !SMP. So jiffies > - * won't get updated when UP machine cpufreq build with > - * CONFIG_SMP enabled. Below code is added only to manage that > - * scenario > - */ > freqs.new = omap_getspeed(policy->cpu); > - if (!is_smp()) { > - loops_per_jiffy = > - cpufreq_scale(loops_per_jiffy, freqs.old, freqs.new); > - cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); > - goto skip_lpj; > - } > > #ifdef CONFIG_SMP > /* > @@ -134,10 +125,24 @@ set_freq: > * cpufreq driver. So, update the per-CPU loops_per_jiffy value > * on frequency transition. We need to update all dependent CPUs. > */ > - for_each_cpu(i, policy->cpus) > + for_each_cpu(i, policy->cpus) { > + struct lpj_info *lpj = &per_cpu(lpj_ref, i); > + if (!lpj->freq) { > + lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy; > + lpj->freq = freqs.old; > + } > + > per_cpu(cpu_data, i).loops_per_jiffy = > - cpufreq_scale(per_cpu(cpu_data, i).loops_per_jiffy, > - freqs.old, freqs.new); > + cpufreq_scale(lpj->ref, lpj->freq, freqs.new); > + } > + > + /* And don't forget to adjust the global one */ > + if (!global_lpj_ref.freq) { > + global_lpj_ref.ref = loops_per_jiffy; > + global_lpj_ref.freq = freqs.old; > + } > + loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq, > + freqs.new); > #endif > > /* notifiers */ > @@ -146,7 +151,6 @@ set_freq: > cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); > } > > -skip_lpj: > return ret; > } -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
