[PATCH v3 4/5] drm/panfrost: devfreq: set opp to the recommended one to configure and enable regulator

Biju Das biju.das.jz at bp.renesas.com
Mon Sep 5 11:17:09 PDT 2022


Hi,

Thanks for the patch.

> Subject: [PATCH v3 4/5] drm/panfrost: devfreq: set opp to the recommended
> one to configure and enable regulator
> 
> devm_pm_opp_set_regulators() doesn't enable regulator, which make
> regulator framework switching it off during regulator_late_cleanup().

In that case, why not regulator_get()for 
Dynamic regulator(non fixed regulator)??

> 
> Call dev_pm_opp_set_opp() with the recommend OPP in
> panfrost_devfreq_init() to enable the regulator and avoid any switch off
> by regulator_late_cleanup().
> 
> Suggested-by: Viresh Kumar <viresh.kumar at linaro.org>
> Signed-off-by: Clément Péron <peron.clem at gmail.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_devfreq.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 5110cd9b2425..67b242407156 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -131,6 +131,14 @@ int panfrost_devfreq_init(struct panfrost_device
> *pfdev)
>  		return PTR_ERR(opp);
> 
>  	panfrost_devfreq_profile.initial_freq = cur_freq;
> +
> +	/* Setup and enable regulator */
> +	ret = dev_pm_opp_set_opp(dev, opp);
> +	if (ret) {
> +		DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
> +		return ret;
> +	}


FYI,
On RZ/G2L mali gpu, we have fixed regulator and
I was able to do GPU OPP transition without any issues previously.

root at smarc-rzg2l:~# cat /sys/class/devfreq/11840000.gpu/trans_stat
     From  :   To
           :  50000000  62500000 100000000 125000000 200000000 250000000 400000000 500000000   time(ms)
*  50000000:         0         0         0         0         0         0         0         1       144
   62500000:         0         0         0         0         0         0         0         0         0
  100000000:         0         0         0         0         0         0         0         9       524
  125000000:         0         0         9         0         0         0         0         3      2544
  200000000:         0         0         0        11         0         0         0        46      3304
  250000000:         1         0         0         0        33         0         0         0      7496
  400000000:         0         0         0         0        16        19         0         0      2024
  500000000:         1         0         0         1         8        15        35         0      4032
Total transition : 208

Cheers,
Biju



More information about the linux-arm-kernel mailing list