Messages in this thread | | | From | "Turquette, Mike" <> | Date | Thu, 15 Mar 2012 23:14:53 -0700 | Subject | Re: [PATCH v3] PM / devfreq: add relation of recommended frequency. |
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On Thu, Mar 15, 2012 at 11:02 PM, MyungJoo Ham <myungjoo.ham@samsung.com> 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 flags", does it. > > With the update, devfreq_recommended_opp() is also updated. > > Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
I know Rafael already said he'd take it but I might as well add:
Reviewed-by: Mike Turquette <mturquette@ti.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> > --- > Changes from v2 > - Updated comments > - Rebased. > > Changes from v1 > - Style update. > > drivers/devfreq/devfreq.c | 42 +++++++++++++++++++++++++++++++++++++--- > drivers/devfreq/exynos4_bus.c | 14 +++++++++--- > include/linux/devfreq.h | 16 ++++++++++++-- > 3 files changed, 61 insertions(+), 11 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index a129a7b..70c31d4 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -83,6 +83,7 @@ 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"); > @@ -94,7 +95,24 @@ int update_devfreq(struct devfreq *devfreq) > if (err) > return err; > > - err = devfreq->profile->target(devfreq->dev.parent, &freq); > + /* > + * Adjust the freuqency with user freq and QoS. > + * > + * List from the highest proiority > + * max_freq (probably called by thermal when it's too hot) > + * min_freq > + */ > + > + if (devfreq->min_freq && freq < devfreq->min_freq) { > + freq = devfreq->min_freq; > + flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ > + } > + if (devfreq->max_freq && freq > devfreq->max_freq) { > + freq = devfreq->max_freq; > + flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ > + } > + > + err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); > if (err) > return err; > > @@ -625,14 +643,30 @@ 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 5862475..281c72a 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -44,6 +44,14 @@ struct devfreq_dev_status { > void *private_data; > }; > > +/* > + * 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 > @@ -54,6 +62,8 @@ struct devfreq_dev_status { > * 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 > @@ -66,7 +76,7 @@ struct devfreq_dev_profile { > unsigned long initial_freq; > unsigned int polling_ms; > > - 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); > @@ -165,7 +175,7 @@ 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, > @@ -216,7 +226,7 @@ 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; > } > -- > 1.7.4.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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