| Message ID | 20200107230626.885451-2-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | devfreq fixes for panfrost | expand |
On 07/01/2020 11:06 pm, Martin Blumenstingl wrote: > Decouple the check to see whether we want to enable devfreq for the GPU > from dev_pm_opp_set_regulators(). This is preparation work for adding > back support for regulator control (which means we need to call > dev_pm_opp_set_regulators() before dev_pm_opp_of_add_table(), which > means having a check for "is devfreq enabled" that is not tied to > dev_pm_opp_of_add_table() makes things easier). Hmm, what about cases like the SCMI DVFS protocol where the OPPs are dynamically discovered rather than statically defined in DT? Robin. > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> > --- > drivers/gpu/drm/panfrost/panfrost_devfreq.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c > index 413987038fbf..1471588763ce 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c > @@ -5,6 +5,7 @@ > #include <linux/platform_device.h> > #include <linux/pm_opp.h> > #include <linux/clk.h> > +#include <linux/property.h> > #include <linux/regulator/consumer.h> > > #include "panfrost_device.h" > @@ -79,10 +80,12 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev) > struct devfreq *devfreq; > struct thermal_cooling_device *cooling; > > - ret = dev_pm_opp_of_add_table(dev); > - if (ret == -ENODEV) /* Optional, continue without devfreq */ > + if (!device_property_present(dev, "operating-points-v2")) > + /* Optional, continue without devfreq */ > return 0; > - else if (ret) > + > + ret = dev_pm_opp_of_add_table(dev); > + if (ret) > return ret; > > panfrost_devfreq_reset(pfdev); >
Hi Robin, On Wed, Jan 8, 2020 at 12:18 PM Robin Murphy <robin.murphy@arm.com> wrote: > > On 07/01/2020 11:06 pm, Martin Blumenstingl wrote: > > Decouple the check to see whether we want to enable devfreq for the GPU > > from dev_pm_opp_set_regulators(). This is preparation work for adding > > back support for regulator control (which means we need to call > > dev_pm_opp_set_regulators() before dev_pm_opp_of_add_table(), which > > means having a check for "is devfreq enabled" that is not tied to > > dev_pm_opp_of_add_table() makes things easier). > > Hmm, what about cases like the SCMI DVFS protocol where the OPPs are > dynamically discovered rather than statically defined in DT? where can I find such an example (Amlogic SoCs use SCPI instead of SCMI, so I don't think that I have any board with SCMI support) or some documentation? (I could only find SCPI clock and CPU DVFS implementations, but no generic "OPPs for any device" implementation) Martin
[ +Sudeep ] On 08/01/2020 12:38 pm, Martin Blumenstingl wrote: > Hi Robin, > > On Wed, Jan 8, 2020 at 12:18 PM Robin Murphy <robin.murphy@arm.com> wrote: >> >> On 07/01/2020 11:06 pm, Martin Blumenstingl wrote: >>> Decouple the check to see whether we want to enable devfreq for the GPU >>> from dev_pm_opp_set_regulators(). This is preparation work for adding >>> back support for regulator control (which means we need to call >>> dev_pm_opp_set_regulators() before dev_pm_opp_of_add_table(), which >>> means having a check for "is devfreq enabled" that is not tied to >>> dev_pm_opp_of_add_table() makes things easier). >> >> Hmm, what about cases like the SCMI DVFS protocol where the OPPs are >> dynamically discovered rather than statically defined in DT? > where can I find such an example (Amlogic SoCs use SCPI instead of > SCMI, so I don't think that I have any board with SCMI support) or > some documentation? > (I could only find SCPI clock and CPU DVFS implementations, but no > generic "OPPs for any device" implementation) On closer inspection I think this applies to the SCPI DVFS protocol too[1]. AIUI the fact that neither is wired up to a devfreq driver yet is merely due to lack of demand and suitable systems to develop/test on so far - the panfrost devfreq code is only now looking like the first viable upstream use-case ;) Robin. [1] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922g/BABFEBCD.html
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c index 413987038fbf..1471588763ce 100644 --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c @@ -5,6 +5,7 @@ #include <linux/platform_device.h> #include <linux/pm_opp.h> #include <linux/clk.h> +#include <linux/property.h> #include <linux/regulator/consumer.h> #include "panfrost_device.h" @@ -79,10 +80,12 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev) struct devfreq *devfreq; struct thermal_cooling_device *cooling; - ret = dev_pm_opp_of_add_table(dev); - if (ret == -ENODEV) /* Optional, continue without devfreq */ + if (!device_property_present(dev, "operating-points-v2")) + /* Optional, continue without devfreq */ return 0; - else if (ret) + + ret = dev_pm_opp_of_add_table(dev); + if (ret) return ret; panfrost_devfreq_reset(pfdev);
Decouple the check to see whether we want to enable devfreq for the GPU from dev_pm_opp_set_regulators(). This is preparation work for adding back support for regulator control (which means we need to call dev_pm_opp_set_regulators() before dev_pm_opp_of_add_table(), which means having a check for "is devfreq enabled" that is not tied to dev_pm_opp_of_add_table() makes things easier). Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- drivers/gpu/drm/panfrost/panfrost_devfreq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)