Ok, I got it. So this patch has no too much use. Thanks Xiaoguang -----Original Message----- From: MyungJoo Ham [mailto:myungjoo.ham@xxxxxxxxxxx] Sent: 2012年6月13日 12:58 To: Xiaoguang Chen; linux-kernel@xxxxxxxxxxxxxxx Cc: 박경민; linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx Subject: Re: [PATCH 2/2] PM: Devfreq: Add frequency get function in profile > when devfreq set one frequency, the final frequency may not the same > as the requested frequency. Add get function in profile to let devfreq > driver return the final frequency. > > Signed-off-by: Xiaoguang Chen <chenxg@xxxxxxxxxxx> That is why in update_freq() function that you've modified uses: err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); not err = devfreq->profile->target(devfreq->dev.parent, freq, flags); The target function will return the configured frequency right there. Calling "__devfreq_get()" at the same location wouldn't help as long as the "target()" callback is implemented correctly. Cheers! MyungJoo > --- > drivers/devfreq/devfreq.c | 12 +++++++++++- > include/linux/devfreq.h | 2 ++ > 2 files changed, 13 insertions(+), 1 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 2144200..50a4fc0 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -72,6 +72,16 @@ static struct devfreq *find_device_devfreq(struct device *dev) > return ERR_PTR(-ENODEV); > } > > +static unsigned long __devfreq_get(struct device *dev) { > + struct devfreq *devfreq = to_devfreq(dev); > + unsigned long ret_freq = devfreq->previous_freq; > + if (!devfreq->profile->get) > + return ret_freq; > + ret_freq = devfreq->profile->get(devfreq->dev.parent); > + return ret_freq; > +} > + > /** > * update_devfreq() - Reevaluate the device and configure frequency. > * @devfreq: the devfreq instance. > @@ -116,7 +126,7 @@ int update_devfreq(struct devfreq *devfreq) > if (err) > return err; > > - devfreq->previous_freq = freq; > + devfreq->previous_freq = __devfreq_get(&devfreq->dev); > return err; > } > > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index > e5e4036..f789314 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -65,6 +65,7 @@ struct devfreq_frequency_table { > * @initial_freq The operating frequency when devfreq_add_device() is > * called. > * @polling_ms The polling interval in ms. 0 disables polling. > + * @get Get the devices's actual frequency > * @target The device should set its operating frequency at > * freq or lowest-upper-than-freq value. If freq is > * higher than any operable frequency, set maximum. > @@ -84,6 +85,7 @@ struct devfreq_dev_profile { > unsigned long initial_freq; > unsigned int polling_ms; > > + unsigned long (*get)(struct device *dev); > int (*target)(struct device *dev, unsigned long *freq, u32 flags); > int (*get_dev_status)(struct device *dev, > struct devfreq_dev_status *stat); > -- > 1.7.0.4 _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
