Messages in this thread | | | Date | Wed, 11 Mar 2020 17:35:19 -0700 | From | Matthias Kaehlcke <> | Subject | Re: [PATCH v2] thermal: devfreq_cooling: Use PM QoS to set frequency limits |
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Is any further action needed from my side or can this land?
Thanks
Matthias
On Fri, Jan 17, 2020 at 02:22:02PM +0900, Chanwoo Choi wrote: > On 1/17/20 8:12 AM, Matthias Kaehlcke wrote: > > Now that devfreq supports limiting the frequency range of a device > > through PM QoS make use of it instead of disabling OPPs that should > > not be used. > > > > The switch from disabling OPPs to PM QoS introduces a subtle behavioral > > change in case of conflicting requests (min > max): PM QoS gives > > precedence to the MIN_FREQUENCY request, while higher OPPs disabled > > with dev_pm_opp_disable() would override MIN_FREQUENCY. > > > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > > --- > > > > Changes in v2: > > - added documentation for 'req_max_freq' > > - fixed jumps in of_devfreq_cooling_register_power() unwind > > - added comment about behavioral change to the commit message > > > > drivers/thermal/devfreq_cooling.c | 70 ++++++++++--------------------- > > 1 file changed, 23 insertions(+), 47 deletions(-) > > > > diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c > > index ef59256887ff63..cbbaf5bc425d1a 100644 > > --- a/drivers/thermal/devfreq_cooling.c > > +++ b/drivers/thermal/devfreq_cooling.c > > @@ -24,11 +24,13 @@ > > #include <linux/idr.h> > > #include <linux/slab.h> > > #include <linux/pm_opp.h> > > +#include <linux/pm_qos.h> > > #include <linux/thermal.h> > > > > #include <trace/events/thermal.h> > > > > -#define SCALE_ERROR_MITIGATION 100 > > +#define HZ_PER_KHZ 1000 > > +#define SCALE_ERROR_MITIGATION 100 > > > > static DEFINE_IDA(devfreq_ida); > > > > @@ -53,6 +55,8 @@ static DEFINE_IDA(devfreq_ida); > > * 'utilization' (which is 'busy_time / 'total_time'). > > * The 'res_util' range is from 100 to (power_table[state] * 100) > > * for the corresponding 'state'. > > + * @req_max_freq: PM QoS request for limiting the maximum frequency > > + * of the devfreq device. > > */ > > struct devfreq_cooling_device { > > int id; > > @@ -65,49 +69,9 @@ struct devfreq_cooling_device { > > struct devfreq_cooling_power *power_ops; > > u32 res_util; > > int capped_state; > > + struct dev_pm_qos_request req_max_freq; > > }; > > > > -/** > > - * partition_enable_opps() - disable all opps above a given state > > - * @dfc: Pointer to devfreq we are operating on > > - * @cdev_state: cooling device state we're setting > > - * > > - * Go through the OPPs of the device, enabling all OPPs until > > - * @cdev_state and disabling those frequencies above it. > > - */ > > -static int partition_enable_opps(struct devfreq_cooling_device *dfc, > > - unsigned long cdev_state) > > -{ > > - int i; > > - struct device *dev = dfc->devfreq->dev.parent; > > - > > - for (i = 0; i < dfc->freq_table_size; i++) { > > - struct dev_pm_opp *opp; > > - int ret = 0; > > - unsigned int freq = dfc->freq_table[i]; > > - bool want_enable = i >= cdev_state ? true : false; > > - > > - opp = dev_pm_opp_find_freq_exact(dev, freq, !want_enable); > > - > > - if (PTR_ERR(opp) == -ERANGE) > > - continue; > > - else if (IS_ERR(opp)) > > - return PTR_ERR(opp); > > - > > - dev_pm_opp_put(opp); > > - > > - if (want_enable) > > - ret = dev_pm_opp_enable(dev, freq); > > - else > > - ret = dev_pm_opp_disable(dev, freq); > > - > > - if (ret) > > - return ret; > > - } > > - > > - return 0; > > -} > > - > > static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev, > > unsigned long *state) > > { > > @@ -134,7 +98,7 @@ static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev, > > struct devfreq_cooling_device *dfc = cdev->devdata; > > struct devfreq *df = dfc->devfreq; > > struct device *dev = df->dev.parent; > > - int ret; > > + unsigned long freq; > > > > if (state == dfc->cooling_state) > > return 0; > > @@ -144,9 +108,10 @@ static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev, > > if (state >= dfc->freq_table_size) > > return -EINVAL; > > > > - ret = partition_enable_opps(dfc, state); > > - if (ret) > > - return ret; > > + freq = dfc->freq_table[state]; > > + > > + dev_pm_qos_update_request(&dfc->req_max_freq, > > + DIV_ROUND_UP(freq, HZ_PER_KHZ)); > > > > dfc->cooling_state = state; > > > > @@ -529,9 +494,15 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, > > if (err) > > goto free_dfc; > > > > - err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL); > > + err = dev_pm_qos_add_request(df->dev.parent, &dfc->req_max_freq, > > + DEV_PM_QOS_MAX_FREQUENCY, > > + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); > > if (err < 0) > > goto free_tables; > > + > > + err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL); > > + if (err < 0) > > + goto remove_qos_req; > > dfc->id = err; > > > > snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id); > > @@ -552,6 +523,10 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, > > > > release_ida: > > ida_simple_remove(&devfreq_ida, dfc->id); > > + > > +remove_qos_req: > > + dev_pm_qos_remove_request(&dfc->req_max_freq); > > + > > free_tables: > > kfree(dfc->power_table); > > kfree(dfc->freq_table); > > @@ -600,6 +575,7 @@ void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) > > > > thermal_cooling_device_unregister(dfc->cdev); > > ida_simple_remove(&devfreq_ida, dfc->id); > > + dev_pm_qos_remove_request(&dfc->req_max_freq); > > kfree(dfc->power_table); > > kfree(dfc->freq_table); > > > > > > Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> > > -- > Best Regards, > Chanwoo Choi > Samsung Electronics
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