Re: [PATCH RFT v1 1/3] drm/panfrost: enable devfreq based the "operating-points-v2" property

From: Robin Murphy
Date: Wed Jan 08 2020 - 06:19:03 EST


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@xxxxxxxxxxxxxx>
---
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);