Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] PM / devfreq: add relation of recommended frequency. | Date | Thu, 15 Mar 2012 01:25:14 +0100 |
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On Wednesday, March 07, 2012, MyungJoo Ham wrote: > The semantics of "target frequency" given to devfreq driver from > devfreq framework has always been interpretted as "at least" or GLB > (greatest lower bound). However, the framework might want the > device driver to limit its max frequency (LUB: least upper bound), > especially if it is given by thermal framework (it's too hot). > > Thus, the target fuction should have another parameter to express > whether the framework wants GLB or LUB. And, the additional parameter, > "u32 options", does it. > > With the update, devfreq_recommended_opp() is also updated. > > Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Can you please prepare a version of this patch that applies cleanly on top of the pm-qos branch of the linux-pm tree?
I'd like to take it for v3.4 if possible.
Thanks, Rafael
> --- > Changes from v1 > - Style update. > --- > drivers/devfreq/devfreq.c | 41 ++++++++++++++++++++++++++++++----------- > drivers/devfreq/exynos4_bus.c | 14 ++++++++++---- > include/linux/devfreq.h | 16 +++++++++++++--- > 3 files changed, 53 insertions(+), 18 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0b49f59..13794d1 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -84,6 +84,7 @@ int update_devfreq(struct devfreq *devfreq) > { > unsigned long freq; > int err = 0; > + u32 flags = 0; > > if (!mutex_is_locked(&devfreq->lock)) { > WARN(true, "devfreq->lock must be locked by the caller.\n"); > @@ -104,18 +105,20 @@ int update_devfreq(struct devfreq *devfreq) > * qos_min_freq > */ > > - if (devfreq->qos_min_freq && freq < devfreq->qos_min_freq) > + if (devfreq->qos_min_freq && freq < devfreq->qos_min_freq) { > freq = devfreq->qos_min_freq; > - if (devfreq->max_freq && freq > devfreq->max_freq) > + flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ > + } > + if (devfreq->max_freq && freq > devfreq->max_freq) { > freq = devfreq->max_freq; > - if (devfreq->min_freq && freq < devfreq->min_freq) > + flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ > + } > + if (devfreq->min_freq && freq < devfreq->min_freq) { > freq = devfreq->min_freq; > + flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ > + } > > - /* > - * TODO in the devfreq-next: > - * add relation or use rance (freq_min, freq_max) > - */ > - err = devfreq->profile->target(devfreq->dev.parent, &freq); > + err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); > if (err) > return err; > > @@ -773,14 +776,30 @@ module_exit(devfreq_exit); > * freq value given to target callback. > * @dev The devfreq user device. (parent of devfreq) > * @freq The frequency given to target function > + * @flags Flags handed from devfreq framework. > * > */ > -struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq) > +struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, > + u32 flags) > { > - struct opp *opp = opp_find_freq_ceil(dev, freq); > + struct opp *opp; > > - if (opp == ERR_PTR(-ENODEV)) > + if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { > + /* The freq is an upper bound. opp should be lower */ > opp = opp_find_freq_floor(dev, freq); > + > + /* If not available, use the closest opp */ > + if (opp == ERR_PTR(-ENODEV)) > + opp = opp_find_freq_ceil(dev, freq); > + } else { > + /* The freq is an lower bound. opp should be higher */ > + opp = opp_find_freq_ceil(dev, freq); > + > + /* If not available, use the closest opp */ > + if (opp == ERR_PTR(-ENODEV)) > + opp = opp_find_freq_floor(dev, freq); > + } > + > return opp; > } > > diff --git a/drivers/devfreq/exynos4_bus.c b/drivers/devfreq/exynos4_bus.c > index 590d686..1a361e9 100644 > --- a/drivers/devfreq/exynos4_bus.c > +++ b/drivers/devfreq/exynos4_bus.c > @@ -619,13 +619,19 @@ static int exynos4_bus_setvolt(struct busfreq_data *data, struct opp *opp, > return err; > } > > -static int exynos4_bus_target(struct device *dev, unsigned long *_freq) > +static int exynos4_bus_target(struct device *dev, unsigned long *_freq, > + u32 flags) > { > int err = 0; > - struct busfreq_data *data = dev_get_drvdata(dev); > - struct opp *opp = devfreq_recommended_opp(dev, _freq); > - unsigned long old_freq = opp_get_freq(data->curr_opp); > + struct platform_device *pdev = container_of(dev, struct platform_device, > + dev); > + struct busfreq_data *data = platform_get_drvdata(pdev); > + struct opp *opp = devfreq_recommended_opp(dev, _freq, flags); > unsigned long freq = opp_get_freq(opp); > + unsigned long old_freq = opp_get_freq(data->curr_opp); > + > + if (IS_ERR(opp)) > + return PTR_ERR(opp); > > if (old_freq == freq) > return 0; > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > index f27d511..85d4b0f 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -59,6 +59,14 @@ struct devfreq_pm_qos_table { > s32 qos_value; > }; > > +/* > + * The resulting frequency should be at most this. (this bound is the > + * least upper bound; thus, the resulting freq should be lower or same) > + * If the flag is not set, the resulting frequency should be at most the > + * bound (greatest lower bound) > + */ > +#define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1 > + > /** > * struct devfreq_dev_profile - Devfreq's user device profile > * @initial_freq The operating frequency when devfreq_add_device() is > @@ -74,6 +82,8 @@ struct devfreq_pm_qos_table { > * higher than any operable frequency, set maximum. > * Before returning, target function should set > * freq at the current frequency. > + * The "flags" parameter's possible values are > + * explained above with "DEVFREQ_FLAG_*" macros. > * @get_dev_status The device should provide the current performance > * status to devfreq, which is used by governors. > * @exit An optional callback that is called when devfreq > @@ -92,7 +102,7 @@ struct devfreq_dev_profile { > int qos_type; > struct devfreq_pm_qos_table *qos_list; > > - int (*target)(struct device *dev, unsigned long *freq); > + int (*target)(struct device *dev, unsigned long *freq, u32 flags); > int (*get_dev_status)(struct device *dev, > struct devfreq_dev_status *stat); > void (*exit)(struct device *dev); > @@ -198,7 +208,7 @@ extern int devfreq_remove_device(struct devfreq *devfreq); > > /* Helper functions for devfreq user device driver with OPP. */ > extern struct opp *devfreq_recommended_opp(struct device *dev, > - unsigned long *freq); > + unsigned long *freq, u32 flags); > extern int devfreq_register_opp_notifier(struct device *dev, > struct devfreq *devfreq); > extern int devfreq_unregister_opp_notifier(struct device *dev, > @@ -253,7 +263,7 @@ static int devfreq_remove_device(struct devfreq *devfreq) > } > > static struct opp *devfreq_recommended_opp(struct device *dev, > - unsigned long *freq) > + unsigned long *freq, u32 flags) > { > return -EINVAL; > } >
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