It was noticed when setting the Panfrost's DVFS device to the performant
governor, GPU frequency as reported by fdinfo had dropped to 0 permamently.
There are two separate issues causing this behaviour:
- Not initialising the device's current_frequency variable to its original
value during device probe().
- Updating said variable in Panfrost devfreq's get_dev_status() rather
than after the new OPP's frequency had been retrieved in target(), which
meant the old frequency would be assigned instead.
Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
Fixes: f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
---
drivers/gpu/drm/panfrost/panfrost_devfreq.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index f59c82ea8870..2d30da38c2c3 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -29,14 +29,20 @@ static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfr
static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
u32 flags)
{
+ struct panfrost_device *ptdev = dev_get_drvdata(dev);
struct dev_pm_opp *opp;
+ int err;
opp = devfreq_recommended_opp(dev, freq, flags);
if (IS_ERR(opp))
return PTR_ERR(opp);
dev_pm_opp_put(opp);
- return dev_pm_opp_set_rate(dev, *freq);
+ err = dev_pm_opp_set_rate(dev, *freq);
+ if (!err)
+ ptdev->pfdevfreq.current_frequency = *freq;
+
+ return err;
}
static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq)
@@ -58,7 +64,6 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
spin_lock_irqsave(&pfdevfreq->lock, irqflags);
panfrost_devfreq_update_utilization(pfdevfreq);
- pfdevfreq->current_frequency = status->current_frequency;
status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time,
pfdevfreq->idle_time));
@@ -164,6 +169,14 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
panfrost_devfreq_profile.initial_freq = cur_freq;
+ /*
+ * We could wait until panfrost_devfreq_target() to set this value, but
+ * since the simple_ondemand governor works asynchronously, there's a
+ * chance by the time someone opens the device's fdinfo file, current
+ * frequency hasn't been updated yet, so let's just do an early set.
+ */
+ pfdevfreq->current_frequency = cur_freq;
+
/*
* Set the recommend OPP this will enable and configure the regulator
* if any and will avoid a switch off by regulator_late_cleanup()
--
2.42.0
