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 <[email protected]>
---
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);
--
2.24.1
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 <[email protected]>
> ---
> 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 <[email protected]> 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 <[email protected]> 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