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 <[email protected]> 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
