Re: [PATCH v2 1/2] drm/panfrost: Add missing OPP table refcnt decremental

From: Steven Price
Date: Thu Oct 03 2024 - 10:51:07 EST


On 03/10/2024 14:30, Adrián Larumbe wrote:
> Commit f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
> retrieves the OPP for the maximum device clock frequency, but forgets to
> keep the reference count balanced by putting the returned OPP object. This
> eventually leads to an OPP core warning when removing the device.
>
> Fix it by putting OPP objects as many times as they're retrieved. That
> includes putting the OPP object in case setting it fails.
>
> Also remove an unnecessary whitespace.
>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
> Fixes: f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")

Reviewed-by: Steven Price <steven.price@xxxxxxx>

> ---
> drivers/gpu/drm/panfrost/panfrost_devfreq.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 2d30da38c2c3..4b8840a41779 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -38,7 +38,7 @@ static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
> return PTR_ERR(opp);
> dev_pm_opp_put(opp);
>
> - err = dev_pm_opp_set_rate(dev, *freq);
> + err = dev_pm_opp_set_rate(dev, *freq);
> if (!err)
> ptdev->pfdevfreq.current_frequency = *freq;
>
> @@ -184,9 +184,12 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> ret = dev_pm_opp_set_opp(dev, opp);
> if (ret) {
> DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
> + dev_pm_opp_put(opp);
> return ret;
> }
>
> + dev_pm_opp_put(opp);
> +
> /* Find the fastest defined rate */
> opp = dev_pm_opp_find_freq_floor(dev, &freq);
> if (IS_ERR(opp))